Page 1: Marine Engines
MAIN MENU SERVICE MANUAL Number 24 MARINE ENGINES GM V-8 305 CID (5.0L) / 350 CID (5.7L) 1999, Mercury Marine Printed in U.S.A. 90-861327--1 1099...
Page 2 MerCruiser #24 GM V-8 90-861327--1 305 CID (5.0L) / 350 CID (5.7L) MerCruiser #24 GM V-8 90-861327--1 305 CID (5.0L) / 350 CID (5.7L)
Page 3 Notice Throughout this publication, “Dangers”, “Warnings” and “Cautions” (accompanied by the In- ternational HAZARD Symbol ) are used to alert the mechanic to special instructions con- cerning a particular service or operation that may be hazardous if performed incorrectly or carelessly.
Page 4 It is important to note, during any maintenance procedure replacement fasteners must have the same measurements and strength as those removed. Numbers on the heads of the met- ric bolts and on the surfaces of metric nuts indicate their strength. American bolts use radial lines for this purpose, while most American nuts do not have strength markings.
Page 5 Service Manual Outline Important Information Section 1 - Important Information A - General Information B - Maintenance Removal and Installation C - Troubleshooting Section 2 - Removal and Installation A - MCM Models B - MIE Models Engine Section 3 - Engine A - 350 cid / 5.0L/ 305 cid / 5.7L Engines Section 4 - Electrical Systems A - Starting System...
Page 6: Table Of Contents
Table of Contents IMPORTANT INFORMATION Section 1A - General Information Table of Contents ..... 1A-1 Propeller Information ....1A-5 Introduction .
Page 7 Section 1C - Troubleshooting Used Spark Plug Analysis ... . 1C-2 Engine Runs Poorly At High RPM ..1C-16 Normal Condition ....1C-2 Engine Acceleration Is Poor .
Page 8 ENGINE Section 3A - 350 cid / 5.0L/ 305 cid / 5.7L Engines Torque Specifications ....3A-3 Valve Seat Repair ....3A-39 Tools .
Page 9: Electrical Systems
ELECTRICAL SYSTEMS Section 4A - Starting System Identification ......4A-2 Exploded View ..... . 4A-13 Replacement Parts Warning .
Page 10 Section 4B - Ignition System Ignition Control System Components 4B-2 Mercury Marine Distributor ... 4B-17 Replacement Parts Warning ..4B-2 Description .
Page 11: Fuel System
Section 4D - Instrumentation Tools ......4D-2 Senders ......4D-9 Lubricants / Sealants / Adhesives .
Page 12  Section 5B - Mercarb 2 Barrel Carburetor Identification ......5B-2 Fuel Inlet Filter ....5B-11 Replacement Parts Warning .
Page 13 Section 5D - Fuel Injection Descriptions And System Operation Special Tools ..... . . 5D-2 Electronic Control Module (ECM) Service Precautions .
Page 14 Section 5F - Fuel Injection System Troubleshooting Scan Tool Normal Specifications (Idle / Warm Detonation / Spark Knock Symptom . . . 5F-11 Engine / Closed Throttle / Neutral) ..5F-2 Hesitation, Sag, Stumble Symptom ..5F-13 Important Preliminary Checks .
Page 15: Cooling System
COOLING SYSTEM Section 6A - Seawater Cooled Models Torque Specifications ....6A-2 Seawater Pump Bearing Housing ..6A-14 Tools ......6A-2 Disassembly .
Page 16: Exhaust System
EXHAUST SYSTEM Section 7A - General Exhaust System Requirements ..7A-2 Exhaust Elbow Risers ... . 7A-2 MCM (Sterndrive) Engines With Thru-Transom Exhaust .
Page 17 Section 8B - Velvet Drive 5000 Series Transmissions Velvet Drive 5000A Down Angle Important Information ....8B-6 Specifications ..... . 8B-2 Engine .
Page 18 POWER STEERING SYSTEM Section 9A - Pump And Related Components Torque Specifications ....9A-2 Important Service Information ..9A-7 Tools .
Page 19: Table Of Contents
SERVICE MANUAL NUMBER 24 GENERAL INFORMATION IMPORTANT INFORMATION Section 1A - General Information Table of Contents Introduction ......1A-2 Propeller Information .
Page 20: Introduction
GENERAL INFORMATION SERVICE MANUAL NUMBER 24 Introduction This comprehensive overhaul and repair manual is designed as a service guide for the mod- els previously listed. It provides specific information, including procedures for disassembly, inspection, assembly and adjustment to enable dealers and service mechanics to repair and tune these engines.
Page 21: How To Read A Parts Manual
SERVICE MANUAL NUMBER 24 GENERAL INFORMATION How to Read a Parts Manual Power Steering Pump Assembly REF. PART NO. SYM. QTY. DESCRIPTION 90507A12 PUMP ASSEMBLY–Power Steering 36- 95805 73873A1 PULLEY 16- 41877 STUD 57- 65607T V-BELT 32- 806684 HOSE–Pressure (FITTINGS ON BOTH ENDS) 25- 89879 O-RING 25- 806232...
Page 22: Directional References
GENERAL INFORMATION SERVICE MANUAL NUMBER 24 Directional References Front of boat is bow; rear is stern. Starboard side is right side; port side is left side. In this maintenance manual, all directional references are given as they appear when viewing boat from stern looking toward bow.
Page 23: Engine Serial Number Locations
Starter Motor Propeller Information Refer to the “Propeller” section in appropriate Mercury MerCruiser Sterndrive Service Manual, or order publication 90-86144-92, “Everything you need to know about propellers.” Changing diameter, pitch or coupling of a propeller will affect engine rpm and boat perfor- mance.
Page 24: Water Testing New Engines
Water Testing New Engines Use care during the first 20 hours of operation on new Mercury MerCruiser engines or possible engine failure may occur. If a new engine has to be water-tested at full throttle before the break-in period is complete, follow this procedure.
Page 25 SERVICE MANUAL NUMBER 24 GENERAL INFORMATION For best speed and minimum spray, the corner between the bottom and the transom should be sharp. 72003 Bottom Corner Transom The bottom is referred to as having a “hook” if it is concave in the fore-and-aft direction. A hook causes more lift on the bottom near the transom and forces the bow to drop.
Page 26: Marine Fouling
IMPORTANT: DO NOT paint anodes or MerCathode System reference electrode and anode, as this will render them ineffective as galvanic corrosion inhibitors. CAUTION Avoid corrosion damage. Do not apply antifouling paint to Mercury MerCruiser drive unit or transom assembly. IMPORTANT: If antifouling protection is required, Tri-Butyl-Tin-Adipate (TBTA) base antifouling paints are recommended on Mercury MerCruiser boating applications.
Page 27: Weight Distribution
SERVICE MANUAL NUMBER 24 GENERAL INFORMATION Weight Distribution Weight distribution is extremely important; it affects a boat’s running angle or attitude. For best top speed, all movable weight - cargo and passengers - should be as far aft as possible to allow the bow to come up to a more efficient angle (3 to 5 degrees).
Page 28 GENERAL INFORMATION SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Index Page 1A-10 90-861327--1 OCTOBER 1999...
Page 29: Table Of Contents
SERVICE MANUAL NUMBER 24 MAINTENANCE IMPORTANT INFORMATION Section 1B - Maintenance Table of Contents Tools ......1B-2 Flushing System MIE Lubricants / Sealants / Adhesives...
Page 30: Tools
MAINTENANCE SERVICE MANUAL NUMBER 24 Tools Description Part Number Timing Light 91-99379 Quicksilver Scan Tool 91-823686A2 Lubricants / Sealants / Adhesives Description Part Number Quicksilver Liquid Neoprene 92-25711--3 Quicksilver 2-4-C Marine Lubricant With 92-825407A3 Teflon Loctite Pipe Sealant With Teflon Obtain Locally Quicksilver U-Joint and Gimbal Bearing 92-828052A2...
Page 31: Maintenance Schedules
In consideration of these factors, Mercury MerCruiser has adjusted some maintenance intervals and corresponding tasks to be performed. In some cases, this may allow for more individual tasks to be performed in a single visit to the serving dealer, rather than multiple visits.
Page 32 MAINTENANCE SERVICE MANUAL NUMBER 24 Gas Sterndrive(Continued) Scheduled Maintenance * Every Every Every Every Every Annu- hours hours ally hours or or 3 or 3 years years Annually years years Touch-up paint power package and spray with corrosion guard. Change crankcase oil and filter. Change drive unit oil and retorque connection of gimbal ring to steering shaft.
Page 33 SERVICE MANUAL NUMBER 24 MAINTENANCE Gas Inboard Routine Maintenance * Each Each Every Weekly Start Months Check crankcase oil (interval can be extended based on experi- ence). If operating in salt, brackish or polluted waters, flush cooling sys- tem after each use. Check transmission fluid.
Page 34 MAINTENANCE SERVICE MANUAL NUMBER 24 Gas Inboard(Continued) Scheduled Maintenance * Every Every Every Every Every hours hours Annu- hours or or 3 or 3 ally Annually years years years years Touch-up paint power package and spray with corrosion guard. Change crankcase oil and filter. Change transmission fluid.
Page 35: Engine And Tune-Up Specifications
Timing must be set using a special procedure as outlined in the appropriate section of this manual. Timing can- not be properly set using the conventional method. A special procedure must be followed to adjust idle rpm. Consult your Authorized Mercury MerCruiser Dealer before attempting this procedure.
Page 36 Timing must be set using a special procedure as outlined in the appropriate section of this manual. Timing can- not be properly set using the conventional method. A special procedure must be followed to check or adjust idle rpm. Consult your Authorized Mercury MerCruiser Dealer before attempting this procedure.
Page 37 Timing must be set using a special procedure as outlined in the appropriate section of this manual. Timing can- not be properly set using the conventional method. A special procedure must be followed to adjust idle rpm. Consult your Authorized Mercury MerCruiser Dealer before attempting this procedure.
Page 38 Timing must be set using a special procedure as outlined in the appropriate section of this manual. Timing can- not be properly set using the conventional method. A special procedure must be followed to adjust idle rpm. Consult your Authorized Mercury MerCruiser Dealer before attempting this procedure.
Page 39: Fluid Capacities
SERVICE MANUAL NUMBER 24 MAINTENANCE Fluid Capacities NOTICE Unit Of Measurement: U.S. Quarts (Liters) All capacities are approximate fluid measures. Sterndrive Engines Model MCM 305 cid / 5.0L and 350 cid / 5.7L Crankcase Oil (With Filter) 5.5 (5.25) Seawater Cooling System 15 (14.1) Closed Cooling System 20 (19)
Page 40 MAINTENANCE SERVICE MANUAL NUMBER 24 Fluid Capacities (Continued) Transmission NOTICE Unit Of Measurement: U.S. Quarts (Liters) All capacities are approximate fluid measures. NOTE: Always use dipstick to determine exact quantity of fluid required. Make and Model Capacity Fluid Type Mobil 424 or Velvet Drive Dexron III Automatic Transmission Fluid 71C In-Line...
Page 41: 20-Hour Break-In Period
(full throttle) rpm. End of First Season Checkup At the end of the first season of operation, an Authorized Mercury MerCruiser Dealer should be contacted to discuss and/or perform various scheduled maintenance items. If you are...
Page 42: Specifications
FUEL RATINGS Mercury MerCruiser engines will operate satisfactorily when using a major brand of unleaded gasoline as follows: USA and Canada - having a posted pump Octane Rating of 87 (R+M)/2 minimum. Premium gasoline [92 (R+M)/2 Octane] is also acceptable.
Page 43 The fuel system components on your Mercury MerCruiser engine will withstand up to 10% alcohol content in the gasoline. We do not know what percentage your boat’s fuel system will withstand.
Page 44: Test For Alcohol Content In Gasoline 1B-16
400 hours, whichever occurs first. All coolants other than Extended Life 5/100 Ethylene Glycol Antifreeze/Coolant must be changed every 2 years or 400 hours, whichever occurs first. Mercury MerCruiser V-8 engines can use any type of permanent antifreeze or any brand antifreeze solution that meets GM specification 1825M. Index...
Page 45: Crankcase Oil
Overfilled crankcases (oil level being too high ) can cause a fluctuation or drop in oil pressure and rocker arm “clatter” on Mercury MerCruiser engines. The over-full condition results in the engine crankshaft splashing and agitating the oil, causing it to foam (become aerated).
Page 46: Checking Engine Oil Level / Filling
MAINTENANCE SERVICE MANUAL NUMBER 24 Checking Engine Oil Level / Filling IMPORTANT: ENGINE CRANKCASE OIL MUST BE CHECKED AT INTERVALS SPECIFIED IN “MAINTENANCE SCHEDULE” CHART. It is normal for an engine to use a certain amount of oil in the process of lubrication and cooling of the engine. The amount of oil consumption is greatly dependent upon engine speed, with consumption being highest at wide-open-throttle and decreasing substantially as engine speed is reduced.
Page 47: Mcm (Sterndrive) Models
SERVICE MANUAL NUMBER 24 MAINTENANCE Changing Water Separating Fuel Filter WARNING Be careful when changing water separating fuel filter. Gasoline is extremely flammable and highly explosive under certain conditions. Be sure ignition key is OFF. Do not smoke or allow spark or open flame in area when changing fuel filter. Wipe up any spilled fuel immediately.
Page 48: Mie (Inboard And Ski) Models
MAINTENANCE SERVICE MANUAL NUMBER 24 2. Remove water separating fuel filter and sealing ring from mounting bracket and discard. 70573 Fuel Filter Sealing Ring 3. Coat sealing ring on new filter with motor oil. 4. Thread filter onto bracket and tighten securely by hand. Do not use a filter wrench. 5.
Page 49: Checking Fluid Level
SERVICE MANUAL NUMBER 24 MAINTENANCE Power Steering System Checking Fluid Level ENGINE WARM 1. Stop engine. Position drive unit so that it is straight back. 2. Remove fill cap / dipstick from power steering pump and note fluid level. 74908 Fill Cap / Dipstick Power Steering Pump 3.
Page 50: Filling And Bleeding
MAINTENANCE SERVICE MANUAL NUMBER 24 Filling and Bleeding IMPORTANT: Power steering system must be filled exactly as explained in the follow- ing to be sure that all air is bled from the system. All air must be removed, or fluid in pump may foam during operation and be discharged from pump reservoir.
Page 51: Closed Cooling System
SERVICE MANUAL NUMBER 24 MAINTENANCE Closed Cooling System Checking Coolant Level CAUTION Allow engine to cool down before removing pressure cap. Sudden loss of pressure could cause hot coolant to boil and discharge violently. After engine has cooled, turn cap 1/4 turn to allow any pressure to escape slowly, then push down and turn cap all the way off.
Page 52: Flushing System Mcm (Sterndrive) . 1B-24
MAINTENANCE SERVICE MANUAL NUMBER 24 Flushing System MCM (Sterndrive) If engine is operated in salty, polluted or mineral-laden water, flush seawater cooling system (preferably after each use) to reduce corrosion and prevent the accumulation of deposits in the system. Thoroughly flush the seawater cooling system prior to storage. NOTE: For additional protection against freezing and rust to the exhaust manifolds and other components, a 50-50 mixture of antifreeze and water can be run through the engine during Power Package Layup.
Page 53: Boat In Water
SERVICE MANUAL NUMBER 24 MAINTENANCE BOAT IN WATER 1. Raise drive unit to full UP position. 2. Install flushing attachment over water pickup holes in gear housing as shown. 3. Attach a water hose between the flushing attachment and a water tap. 72693 Flushing Attachment Hose...
Page 54 MAINTENANCE SERVICE MANUAL NUMBER 24 Flushing System MIE (Inboard and Ski) CAUTION If boat is in the water, seacock, if so equipped, must remain closed until engine is to be re-started, to prevent water from flowing back into cooling system and/or boat. If boat is not fitted with a seacock, water inlet hose must be left disconnected and plugged (to prevent water from flowing back into cooling system and/or boat).
Page 55: Transmission Fluid
SERVICE MANUAL NUMBER 24 MAINTENANCE Transmission Fluid NOTE: Due to the various installation angles and oil cooler set-ups, it may be necessary to adjust oil level. WARNING Do not remove dipstick with engine running. Hot oil can cause burns. CAUTION Clean around the area of the dipstick before removing.
Page 56: Lubrication
MAINTENANCE SERVICE MANUAL NUMBER 24 Lubrication Throttle Cable 1. Lubricate pivot points and guide contact surfaces with SAE 30W motor oil. 71359 74941 2 Barrel Carbureted Models EFI Models Pivot Points Guide Contact Surface Shift Cable and Transmission Linkage MCM (STERNDRIVE) MODELS guide contact surfaces 1.
Page 57: Mie (Inboard And Ski) Models
SERVICE MANUAL NUMBER 24 MAINTENANCE MIE (INBOARD AND SKI) MODELS guide contact surfaces 1. Lubricate pivot points and with SAE 30W motor oil. 72528 Typical Shift Cable Pivot Points Guide Contact Surface 2. Lubricate detent ball and holes in lever with SAE 30W motor oil. 71457 Typical In-Line Transmission Poppet Ball Locations...
Page 58: Engine Coupler/U-Joint Shaft Splines 1B-30
Spline Grease, 92-816391A4; universal joints are greased with Quicksilver 2-4-C Marine Lubricant. NOTE: Refer to Mercury MerCruiser Sterndrive Service Manual for sterndrive unit removal and installation, if necessary. IMPORTANT: Sterndrive Unit does not have to be removed to grease coupler.
Page 59: Sterndrive Drive Shaft Extension Models
SERVICE MANUAL NUMBER 24 MAINTENANCE Sterndrive Drive Shaft Extension Models 72018 72028 Transom End Engine End Grease Fitting Starter Motor MIE (INBOARD AND SKI) MODELS WARNING When performing the following procedure, be sure to observe the following: • Be sure that engine compartment is well ventilated and that no gaso- line vapors are present to avoid the possibility of a fire.
Page 60: Cleaning Flame Arrestor
MAINTENANCE SERVICE MANUAL NUMBER 24 Cleaning Flame Arrestor WARNING Avoid gasoline fire or explosion. Gasoline is extremely flammable and highly explosive under certain conditions. Be careful when cleaning flame arrestor and crankcase ventilation hoses. Be sure that ignition is OFF. DO NOT smoke or allow sources of spark or open flame in area when cleaning flame arrestor and crankcase ventilation hoses.
Page 61: Black Scorpion Flame Arrestor
SERVICE MANUAL NUMBER 24 MAINTENANCE Black Scorpion Flame Arrestor 1. Remove clamp or nut, as applicable. 2. Remove crankcase ventilation hose. 3. Remove flame arrestor. 75046 Earlier Style Flame Arrestor Flame Arrestor Clamp Vent Hose 75779 Later Style Flame Arrestor Flame Arrestor Vent Hose 4.
Page 62: Serpentine Drive Belt
MAINTENANCE SERVICE MANUAL NUMBER 24 Serpentine Drive Belt Component Location WARNING Avoid possible serious injury. Make sure engine is shut off and ignition key is removed before inspecting belt. IMPORTANT: MIE ENGINES ONLY: The brackets and washers on the 3 idler pulleys must be in a certain order or the belt will come off of the serpentine belt.
Page 63 SERVICE MANUAL NUMBER 24 MAINTENANCE NOTE: Some models will have components arranged in a different order. All configurations are not shown. Checking, replacing and adjustment procedures are the same. 76389 Typical Inboard Model Idler Pulley Seawater Pump Pulley Crankshaft Pulley Circulating Pump Pulley Alternator Pulley 76463...
Page 64: Inspection
MAINTENANCE SERVICE MANUAL NUMBER 24 Inspection 1. Inspect drive belt for the following: • Excessive wear • Cracks NOTE: Minor, transverse cracks (across the belt width) may be acceptable. Longitudinal cracks (in direction of belt length) that join transverse cracks are NOT acceptable. •...
Page 65: Ignition Timing
SERVICE MANUAL NUMBER 24 MAINTENANCE 7. While holding adjustment stud at the correct belt tension, tighten 5/8 in. locking nut. 8. Run engine for a short period of time and recheck belt adjustment. 7490 5/8 in. Locking Nut 5/16 in Adjusting Stud Ignition Timing Thunderbolt V Models 1.
Page 66: Efi/Mpi Models
MAINTENANCE SERVICE MANUAL NUMBER 24 12. Restart the engine, increase rpm to 1300 then return to idle positin slowly and shut the engine off. Ensure that the carburetor throttle lever came back against the idle rpm screw. 13. Shut engine off. EFI/MPI Models 1.
Page 67: Cold Weather Or Extended Storage
SERVICE MANUAL NUMBER 24 MAINTENANCE Cold Weather or Extended Storage Precautions WARNING BE CAREFUL while working on fuel system; gasoline is extremely flammable and highly explosive under certain conditions. Be sure that ignition key is OFF and do not smoke or allow sources of spark and/or open flames in the area. WARNING Avoid Fire or Explosion: To prevent a potential fire hazard, be sure that engine com- partment is well ventilated and that there are no gasoline vapors present during...
Page 68: Power Package Layup
IMPORTANT: Mercury MerCruiser strongly recommends that this service be per- formed by an Authorized Mercury MerCruiser Dealer. Damage caused by freezing IS NOT covered by the MerCruiser Limited Warranty. 1. Fill fuel tank(s) with fresh gasoline that does not contain alcohol and a sufficient amount of Quicksilver Gasoline Stabilizer for Marine Engines to treat gasoline.
Page 69 SERVICE MANUAL NUMBER 24 MAINTENANCE 8. Prepare EFI fuel system for extended storage as follows: a. Allow engine to cool down. b. Remove the water separating fuel filter. c. Pour out a small amount of fuel into a suitable container, then add approximately 2 fluid ounces (60 ml) of Quicksilver 2-Cycle Outboard Oil to fuel in the water separat- ing fuel filter.
Page 70: Draining Instructions
MAINTENANCE SERVICE MANUAL NUMBER 24 Draining Instructions DRAINING SEAWATER (RAW-WATER) COOLED MODELS NOTICE Refer to “Cold Weather or Extended Storage Precautions” in this section, BEFORE proceeding. MCM (Sterndrive) Models: 1. Engine must be as level as possible to ensure complete draining of cooling system. 2.
Page 71 SERVICE MANUAL NUMBER 24 MAINTENANCE 4. Repeatedly clean out drain holes using a stiff piece of wire. Do this until entire system is drained. NOTE: It may be necessary to lift, bend, or lower hoses to allow water to drain completely when hoses are disconnected.
Page 72 If NOT equipped with seacock: Seawater inlet hose must remain disconnected and plugged until engine is to be restarted. IMPORTANT: Mercury MerCruiser recommends that propylene glycol antifreeze (nontoxic and biodegradable) be used in sea-water section of the cooling system for cold weather or extended storage.
Page 73 SERVICE MANUAL NUMBER 24 MAINTENANCE DRAINING SEAWATER (RAW-WATER) COOLED MIE (Inboard and Ski) Models: NOTICE Refer to “Cold Weather or Extended Storage Precautions” in this section, BEFORE proceeding. 1. Engine must be as level as possible to ensure complete draining of cooling system. 2.
Page 74 MAINTENANCE SERVICE MANUAL NUMBER 24 4. Repeatedly clean out drain holes using a stiff piece of wire. Do this until entire system is drained. NOTE: It may be necessary to lift, bend, or lower hoses to allow water to drain completely when hoses are disconnected.
Page 75 If NOT equipped with seacock: Seawater inlet hose must remain disconnected and plugged until engine is to be restarted. IMPORTANT: Mercury MerCruiser recommends that propylene glycol antifreeze (nontoxic and biodegradable) be used in sea-water section of the cooling system for cold weather or extended storage.
Page 76: Draining Seawater Section Of Closed Cooled (Coolant) Models
MAINTENANCE SERVICE MANUAL NUMBER 24 DRAINING SEAWATER SECTION OF CLOSED COOLED (COOLANT) MODELS MCM (Sterndrive) Models NOTICE Refer to “Cold Weather or Extended Storage Precautions” in this section, BEFORE proceeding. IMPORTANT: Drain seawater section of closed cooling system only. 1. Engine must be as level as possible to ensure complete draining of cooling system. NOTE: Only if Extended Life 5/100 Ethylene Glycol Antifreeze/Coolant is used.
Page 77 SERVICE MANUAL NUMBER 24 MAINTENANCE 4. Remove seawater pump inlet hose. 75533 Seawater Inlet Hose Hose To Cooler 5. Remove end caps, sealing washers and gaskets from the heat exchanger. Allow tubes to drain. 71515 Heat Exchanger Sealing Washer End Cap Gasket IMPORTANT: Use compressed air to blow any remaining water from the tubes in the heat exchanger.
Page 78: Draining Seawater Section Of Closed Cooled (Coolant) Models
MAINTENANCE SERVICE MANUAL NUMBER 24 DRAINING SEAWATER SECTION OF CLOSED COOLED (COOLANT) MODELS MIE (Inboard and Ski) Models NOTICE Refer to “Cold Weather or Extended Storage Precautions” in this section, BEFORE proceeding. 1. Ensure that the boat is as level as possible to ensure complete draining of cooling sys- tem.
Page 79 SERVICE MANUAL NUMBER 24 MAINTENANCE 5. Remove end caps, sealing washers and gaskets from the heat exchanger. Allow tubes to drain. 71515 Heat Exchanger Sealing Washer End Cap Gasket IMPORTANT: Use compressed air to blow any remaining water from the tubes in the heat exchanger.
Page 80: Draining Sterndrive
MAINTENANCE SERVICE MANUAL NUMBER 24 Draining Sterndrive NOTICE Predelivery Preparation Instructions Must Be Performed Before Delivering Boat To The Product Owner. 1. On Bravo Drive Equipped Models: Insert a small wire (repeatedly) to make sure that speedometer pitot tube, anode cavity vent hole, and anode cavity drain passage are unobstructed and drained.
Page 81: Recommissioning
SERVICE MANUAL NUMBER 24 MAINTENANCE Recommissioning NOTICE Refer to “Cold Weather or Extended Storage Precautions” in this section BEFORE proceeding. 1. Ensure that all cooling system hoses are connected and tight. 2. Ensure all petcocks and drain plugs are installed and tight. 3.
Page 82 MAINTENANCE SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 1B-54 90-861327--1 OCTOBER 1999...
Page 83 SERVICE MANUAL NUMBER 24 TROUBLESHOOTING IMPORTANT INFORMATION Section 1C - Troubleshooting Table of Contents Used Spark Plug Analysis ... . 1C-2 Engine Runs Poorly At High RPM ..1C-16 Normal Condition .
Page 84: Used Spark Plug Analysis
TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Used Spark Plug Analysis Use the following illustrations for determining serviceability of spark plug. Spark plug condi- tion also can suggest a variety of possible engine malfunctions and, therefore, can indicate needed engine repairs. When old plugs are replaced, replace entire set. Perform plug ser- vice only on those plugs suitable for additional service, using the following procedures: 1.
Page 85: Wet Fouling (Oil Deposits)
SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Wet Fouling (Oil Deposits) Plug becomes shorted by excessive oil entering combustion chamber, usually in engine with many hours of operation. Worn piston rings, cylinder walls, valve guides or valve stem seals are causes of oil entering combustion chamber. Only engine repairs will permanently relieve oil wet fouling.
Page 86: High Speed Glazing
TROUBLESHOOTING SERVICE MANUAL NUMBER 24 High Speed Glazing Insulator has yellowish, varnish-like color, indicating that temperatures suddenly have risen, usually during hard, fast acceleration under heavy load. Normal deposits do not get a chance to blow off. Instead, they melt and form a conductive coating. Replace spark plugs. If condition recurs, use colder heat range plug and service plugs more frequently.
Page 87: Reversed Coil Polarity
SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Reversed Coil Polarity Concave erosion of ground electrode is an indication of reversed polarity. Center electrode will show only normal wear. Engine will misfire and idle rough. To correct, reverse primary coil leads. Replace spark plugs. 72422 Splashed Deposits Spotted deposits, which sometimes occur after long delayed tune-up, accumulate after a...
Page 88: Poor Boat Performance And/Or Poor Maneuverability
TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Poor Boat Performance And/Or Poor Maneuverability Symptom Cause A. Improper drive unit trim angle B. Improper weight distribution C. Boat is underpowered D. Permanent or power hook in boat bot- Bow too low E. False bottom full of water F.
Page 89: Improper Full Throttle Engine Rpm
SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Improper Full Throttle Engine RPM RPM Too High Cause Special Information Damaged, pitch too low, diameter too Propeller small, propeller hub slipping Water pickup or through hull fittings mounted too close to propeller (ventila- tion); keel located too close to propeller Boat and/or too deep in the water (ventilation).
Page 90: Engine Cranks Over But Will Not Start Or Starts Hard
TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Engine Cranks Over But Will Not Start Or Starts Hard NOTE: This troubleshooting chart applies to carbureted engines only. For EFI engines, refer to SECTION 5F-“Fuel Injection System Troubleshooting.” Important Information 1. First, determine which engine system is causing the problem. To make an engine operate, basic components - fuel, spark (ignition), and compression - are required.
Page 91: Testing Thunderbolt V Ignition System
SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Testing Thunderbolt V Ignition System Check to ensure that tachometer GRY lead is not shorted to ground (-) at the tachometer or within the harness. No Spark Check all terminal connections at distributor, ignition module and ignition coil. Battery OK? Distributor clamping screw tight? No Spark...
Page 92: Fuel System Rich
TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Fuel System Rich Cause Special Information Fuel boils out of float bowl when shut off Warm engine carburetor percolation and warm. Floods intake manifold. Clogged flame arrestor Automatic choke not opening Float adjustment Float leaks or is saturated with fuel Needle and seat leaking Carburetor gaskets leaking Excessive fuel pump pressure...
Page 93: Engine Will Not Crank Over
SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Engine Will Not Crank Over Cause Special Information Remote control lever not in neutral posi- tion Battery charge low, damaged wiring, loose electrical connections Circuit breaker tripped Blown fuse Ignition switch Slave solenoid Faulty neutral start safety switch Open circuit Starter solenoid Starter motor...
Page 94: Noisy Alternator
TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Noisy Alternator Cause Special Information Loose mounting bolts Drive belt Worn, frayed, loose Loose drive pulley Worn or dirty bearings Faulty diode trio or stator Instrumentation Malfunction Cause Special Information Faulty wiring, loose or corroded terminals Faulty key switch Test, as outlined in SECTION 4D Faulty gauge...
Page 95: Poor Fuel Economy
SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Poor Fuel Economy Cause Special Information Fuel leaks Prolonged idling, slow acceleration, failure to cut back on throttle once boat is on Operator habits plane, boat overloaded, uneven weight distribution Bent, damaged or wrong propeller. Water Engine laboring test boat for proper operating rpm at wide- open-throttle...
Page 96: Carburetor Malfunctions
TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Carburetor Malfunctions Symptoms Cause Needle and seat broken or damaged Float adjustment Saturated float Gaskets leaking Flooding Cracked fuel bowl Fuel percolation Automatic choke malfunctioning Idle rpm too low Idle mixture screws improperly adjusted Idle passages dirty Rough idle Throttle valves worn or damaged Engine flooding...
Page 97: Engine Runs Poorly At Idle
SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Engine Runs Poorly at Idle Symptoms Cause Main metering jets clogged or improperly sized Leaking gaskets Float adjustment Engine surges Saturated float Power valve broken or improperly adjusted Throttle valves worn or damaged Power valve broken or improperly adjusted Float adjustment Low top speed or lack of power...
Page 98: Engine Runs Poorly At High Rpm
TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Engine Runs Poorly At High RPM Cause Special Information Also refer to “Poor Boat Performance” Check oil level with boat at rest in the Crankcase overfilled with oil water Anti-siphon valve Restricting fuel supply Plugged fuel tank vent Improper fuel supply Refer to “Carburetor Malfunctions”...
Page 99: Engine Acceleration Is Poor
SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Engine Acceleration Is Poor Cause Special Information Also refer to “Poor Boat Performance” Idle mixture screws improperly adjusted Incorrect ignition timing Incorrect distributor or amplifier advance Refer to SECTION 4B curve Check for stream of raw fuel from acceler- Accelerator pump ator pump discharge nozzle, when open- ing throttle with engine shut off...
Page 100: Engine Noise
TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Engine Noise Important Information No definite rule or test will positively determine source of engine noise. Use the following information only as a general guide to engine noise diagnosis. 1. Use a timing light to determine if noise is timed with engine speed or 1/2 engine speed. Noises timed with engine speed are related to crankshaft, rods, pistons, piston pins and flywheel.
Page 101: Cylinder Area
SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Cylinder Area Noise Location Possible Causes Sticking valve Carbon build-up Connecting rod installed wrong Cylinder area, may be confined to one Bent connecting rod cylinder or found in more than one Piston damaged or broken cylinder, timed to engine speed Piston rings damaged or broken Piston pin damaged or broken...
Page 102: Crankshaft Area
TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Crankshaft Area Noise Location Possible Causes Crankshaft timing sprocket damaged Timing chain damaged Crankshaft area, front of engine, timed to Crankshaft area, front of engine, timed to engine speed Main bearing damaged Rod bearing damaged Crankshaft striking pan or pan baffle Crankshaft area, center of engine, timed Main bearing damaged...
Page 103 SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Miscellaneous Noise Possible Causes Advanced timing Low octane fuel Engine spark knock Engine running hot Carbon deposits in engine Wrong ignition timing Carburetor set too lean Faulty accelerator pump Vacuum leak Popping through carburetor Valve adjustment Valve timing Burned or stuck valve Vacuum leak...
Page 104 TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Oil Pressure Cause Special Information Use a good automotive oil pressure test Measuring oil pressure gauge. Do not rely on the oil pressure gauge in the boat. Check engine oil level with boat at rest in Oil level should be between the ADD and the water FULL marks...
Page 105: Low Oil Pressure
SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Low Oil Pressure Cause Special Information Low oil level in crankcase Verify with an automotive test gauge. Defective oil pressure gauge and/or Refer to SECTION 4D for instrument sender testing. Oil broken down, contains water or gas, wrong viscosity, engine running too hot or Thin or diluted oil too cold, excessive idling in cold water...
Page 106: Excessive Oil Consumption
TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Excessive Oil Consumption Cause Special Information One quart of oil consumed in 5-15 hours Normal consumption of operation at WOT (especially in a new or rebuilt engine) is normal Clean bilge, run engine with clean white Oil leaks paper on bilge floor, locate oil leak(s) Oil too thin...
Page 107: Water In Engine
SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Water In Engine Important Information IMPORTANT: First determine location of water in engine. This information can be of great help when trying to determine where the water came from and how it got into the engine. The three most common problems are water on top of pistons, water in crankcase oil, water in crankcase oil and on top of pistons.
Page 108 TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Water on Top of Pistons Cause Special Information Operator shut engine off at high rpm Engine out of tune, poor fuel, high idle Engine “diesels” or tries to run backwards rpm, timing set too high NOTE: The term “diesel”...
Page 109 SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Engine Overheats (Mechanical) Cause Special Information Engine rpm below specifications at wide- Damaged or wrong propeller, growth on open-throttle (engine laboring) boat bottom, false bottom full of water Wrong ignition timing Timing too far advanced or retarded Sticking distributor advance weights Spark plug wires crossed (wrong firing order)
Page 110 TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Engine Overheats (Cooling System) Cause Special Information IMPORTANT: The first step is to verify if the engine is actually overheating or the temperature gauge or sender is faulty. IMPORTANT: Best way to test gauge or sender is to replace them. Loose or faulty drive belt Seawater shutoff valve partially or fully closed (if equipped)
Page 111 SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Insufficient Water Flow from Belt Driven Seawater Pickup Pump Cause Special Information Drive belt Loose, worn or broken Seawater shutoff valve partially or fully closed Clogged or improperly installed sea strainer Pump will suck air, pump may fail to prime Loose hose connections between seawa- or will force air bubbles into cooling sys- ter pickup and seawater pump inlet...
Page 112: Power Steering
TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Power Steering Poor, Erratic, or No Assist Cause Special Information Drive belt Worn, broken or out of adjustment Fluid level Air leak in lines, pump, or air from installa- Air in system tion. Refer to SECTION 9A for bleeding procedure.
Page 113: Noisy Pump
SERVICE MANUAL NUMBER 24 TROUBLESHOOTING Noisy Pump Cause Special Information Drive belt Check belt tension Low fluid level Air leak in lines, pump, or air form installa- Air in fluid tion Use stethoscope to listen for noise in Faulty pump pump Kinks or debris in hoses or debris in pas- Restricted fluid passages...
Page 114: Troubleshooting Silent Choice Exhaust Silencer System
TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Troubleshooting Silent Choice Exhaust Silencer System 72533 72534 Air Cylinder Assembly Air Pump Solenoid Check Valve Relief Valve Air Intake Valve Mode Switch Index Page 1C-32 90-861327--1 OCTOBER 1999...
Page 115: Compressor Will Not Run - Testing Mode Switch
SERVICE MANUAL NUMBER 24 TROUBLESHOOTING NOTE: Perform the following tests with engine(s) not running. Compressor Will Not Run - Testing Mode Switch Cause Special Information PUR wire does not have battery voltage Fuse is blown or wiring is faulty BRN wire does not have battery voltage when mode switch is held in THRU-TRAN- Switch is faulty SOM position...
Page 116 TROUBLESHOOTING SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 1C-34 90-861327--1 OCTOBER 1999...
Page 117: Removal And Installation
SERVICE MANUAL NUMBER 24 MCM MODELS REMOVAL AND INSTALLATION Section 2A - MCM Models Table of Contents Torque Specifications ....2A-2 Alignment ......2A-15 Tools .
Page 118: Torque Specifications
MCM MODELS SERVICE MANUAL NUMBER 24 Torque Specifications Fastener Location lb-in. lb-ft Cable Barrel Spread Cotter Key Drive Unit Shift Cable End Cable See Note Guide Hose Clamps Securely Rear Engine Mounts Power Steering Fluid Hose Fitting Cable Barrel Securely Remote Control Cable End Shift Cables...
Page 119: Preparation
SERVICE MANUAL NUMBER 24 MCM MODELS Preparation CAUTION DO NOT use an alignment tool from another manufacturer. Alignment tools other than Quicksilver Alignment Tools (91-805475A1 or a properly modified 91-57797A3) may cause improper alignment and damage to gimbal bearing and/or engine cou- pler.
Page 120 MCM MODELS SERVICE MANUAL NUMBER 24 12. If equipped, remove top and then bottom drive shaft shields at engine end of extension drive shaft. 72033 Top Shield Bottom Shield 4 Bolts / Nuts (2 Hidden) 3 Screws (Hidden) 13. Mark extension drive shaft U-joint yoke / output flange connections at engine end (to assist in exact same positioning during reassembly).
Page 121: Installation
SERVICE MANUAL NUMBER 24 MCM MODELS WARNING Be careful when working on fuel system. Gasoline is extremely flammable and highly explosive under certain conditions. Do not smoke or allow spark or open flame in area. Wipe up any spilled fuel immediately. IMPORTANT: To avoid the need for a complete realignment (after engine repair), DO NOT CHANGE FRONT AND REAR MOUNT ADJUSTMENT.
Page 122 MCM MODELS SERVICE MANUAL NUMBER 24 5. Lubricate engine coupler splines with Quicksilver Engine Coupler Spline Grease. 72023 Double Wound Lockwasher Fiber Wound Lockwasher (Cemented In Place) Inner Transom Plate Mount (Engine Support) Locknuts (Engine Mounting Bolts) CAUTION Center lifting eye (located on top of thermostat housing) is used for engine align- ment only.
Page 123: Drive Shaft Extension Models
SERVICE MANUAL NUMBER 24 MCM MODELS CAUTION When lowering engine into position DO NOT set engine on shift cable. Shift cable outer casing can be crushed causing difficult or improper shifting. 10. Set engine down on stringers and relieve hoist tension. Disconnect sling from engine lifting eyes and switch sling to center lifting eye.
Page 124 MCM MODELS SERVICE MANUAL NUMBER 24 5. As shown, align engine output flange to driveshaft flange exactly as marked during dis- assembly. Torque fasteners to 50 lb-ft (68 Nm). 70237 Engine End Shown Output Shaft Flange Drive Shaft 4 Bolt 7/16-20 x 1-1/2 In. (38 mm) Long 4 Nut 7/16 In.-20 Matching Marks Made Upon Disassembly IMPORTANT: Failure to properly position output shaft flange may result in bearing...
Page 125 SERVICE MANUAL NUMBER 24 MCM MODELS 7. Position engine for correct engine and drive shaft lateral alignment as follows: a. Measure the length of “a” and “b” to the centers of bolt holes. They MUST BE EQUAL. If they are not equal, slide the aft and forward ends of the engine equal amounts in opposite directions to obtain equal lengths for “a”...
Page 126: Engine Mount Adjustment Was Disturbed During Service
MCM MODELS SERVICE MANUAL NUMBER 24 ENGINE MOUNT ADJUSTMENT WAS DISTURBED DURING SERVICE NOTE: A Universal Protractor is recommended for measuring the angles in the following steps. IMPORTANT: In the following steps, the protractor readings will be taken off of vertical and horizontal surfaces;...
Page 127 SERVICE MANUAL NUMBER 24 MCM MODELS NOTE: For ease of installation we recommend the use of a chain leveler in the following steps. 3. Adjust engine mounts so that an equal amount of up and down adjustment exists. 4. Attach a suitable lifting chain to lifting eyes on engine and adjust so that engine will be level when suspended, then place engine into its approximate position (in boat) using an overhead hoist.
Page 128 MCM MODELS SERVICE MANUAL NUMBER 24 8. Relieve hoist tension from engine, then slide engine fore or aft as needed to obtain 1/4 in. (6 mm) between flange shoulder and extension shaft housing bearing, as shown. 72591 Flange Shoulder Bearing 1/4 in.
Page 129 SERVICE MANUAL NUMBER 24 MCM MODELS 11. Position protractor on starter housing cover plate, as shown. Now, raise or lower front engine mount adjusting nuts as required so that protractor needle reads exactly the same number of degrees as that recorded in Step 1. 72593 Thru-Prop Exhaust Shown Flywheel Housing...
Page 130 MCM MODELS SERVICE MANUAL NUMBER 24 14. Apply Loctite 27131 to threads of bottom drive shaft shield retaining screws and install bottom shields on engine and transom end as shown. Torque screws to 30 lb-ft (41 Nm). Then install both top shields as shown. Torque bolts and nuts to 30 lb-ft (41 Nm). 70245 Top Shield and Bottom Shield at Transom End (Engine End Similar) Top Shield...
Page 131: Alignment
SERVICE MANUAL NUMBER 24 MCM MODELS Alignment CAUTION DO NOT use an alignment tool from another manufacturer. Alignment tools other than Quicksilver Alignment Tool 91-805475A1, may cause improper alignment and damage to gimbal bearing and/or engine coupler. CAUTION To avoid damage to gimbal bearing, engine coupler, or alignment tool: •...
Page 132 MCM MODELS SERVICE MANUAL NUMBER 24 d. Adjust front engine mounts until they rest on boat stringers. e. Relieve hoist tension entirely and fasten both front mounts to boat stringer using appropriate hardware (lag bolts or through-bolts, etc.). Recheck alignment with alignment tool. Tool must enter coupler splines freely. If not, readjust front mounts.
Page 133: Water Hose Connections
SERVICE MANUAL NUMBER 24 MCM MODELS b. On Engines with Thru-Transom Exhaust: NOTICE (THRU-TRANSOM EXHAUST) Exhaust hoses must be connected to exhaust elbows so that they do not restrict the flow of discharge water from exhaust elbow. If hoses are connected incorrectly, discharge water from exhaust elbow will not flow around entire inside diameter of hose.
Page 134: Electrical Connections
MCM MODELS SERVICE MANUAL NUMBER 24 ELECTRICAL CONNECTIONS 1. Connect instrument harness to engine harness with hose clamp. Tighten clamp securely. 74754 Engine Wiring Harness Receptacle Bracket 2. Connect trim position sender leads from gimbal housing to leads from engine harness. 72582 BROWN/WHITE (From Engine Harness) BLACK (From Engine Harness)
Page 135 SERVICE MANUAL NUMBER 24 MCM MODELS 3. Connect continuity wire between transom plate and engine ground (–) stud. 71651 Continuity Wire Engine Ground (-) Stud 4. Reconnect shift cut-out switch harness to engine harness. 72034 Engine Harness Switch Harness BLACK WHITE/GREEN (or GRAY) 5.
Page 136: Fuel Supply Connections
MCM MODELS SERVICE MANUAL NUMBER 24 7. Connect battery cables to battery by FIRST connecting positive (+) battery cable (usually RED) to positive (+) battery terminal. Tighten clamp securely. Then, connect negative (–) battery cable (usually BLACK) to negative (–) battery terminal. Tighten clamp securely.
Page 137: Throttle Cable Installation And Adjustment
SERVICE MANUAL NUMBER 24 MCM MODELS 2. On EFI Models, connect the fuel line to fuel filter adapter as shown. 75036 EFI Models Fuel Inlet Hose Connects Here Fuel Filter Cover THROTTLE CABLE INSTALLATION AND ADJUSTMENT 1. Connect throttle cable using hardware retained and adjust as follows: a.
Page 138 MCM MODELS SERVICE MANUAL NUMBER 24 d. Place remote control throttle lever in the WOT position. Ensure that throttle shutters (valves) are completely open and throttle shaft lever contacts carburetor body cast- ing. 71711 Fuel Injection Models Flat Washer and Locknut Cable Barrel Flat Washer And Locknut e.
Page 139: Power Steering Connections
SERVICE MANUAL NUMBER 24 MCM MODELS POWER STEERING CONNECTIONS IMPORTANT: After fluid hose installation in the following, bleed power steering sys- tem as outlined in SECTION 1B - “Maintenance” of this manual, or refer to the appro- priate Sterndrive Service Manual. CAUTION Route hoses exactly as shown below.
Page 140: Exhaust Hose Connections
MCM MODELS SERVICE MANUAL NUMBER 24 EXHAUST HOSE CONNECTIONS 1. Using double hose clamps on all connections, install exhaust hoses and exhaust tubes as shown in “a” or “b” following. Tighten all hose clamps securely. a. On Engines with Thru-Prop Exhaust: 72027 Starboard Side Engine End Shown (Port Similar) Exhaust Pipe...
Page 141 SERVICE MANUAL NUMBER 24 MCM MODELS b. On Engines with Thru-Transom Exhaust: NOTICE (Thru-TRANSOM EXHAUST) Exhaust hoses must be connected to exhaust elbows so that they do not restrict the flow of discharge water from exhaust elbow. If hoses are connected incorrectly, discharge water from exhaust elbow will not flow around entire inside diameter of hose.
Page 142 MCM MODELS SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 2A-26 90-861327--1 OCTOBER 1999...
Page 143: Identification
SERVICE MANUAL NUMBER 24 MIE MODELS REMOVAL AND INSTALLATION SECTION 2B - MIE Models Table of Contents Identification ......2B-2 Preparation .
Page 144 MIE MODELS SERVICE MANUAL NUMBER 24 Identification Velvet Drive In-Line and V-Drive Transmissions On Velvet Drive In-Line and V-Drive Transmissions (71C, 72C, 72C V-Drive, with or without Walter transmissions) the gear ratio (in forward gear) is marked on transmission identification plate. Transmission output shaft rotation and propeller rotation required (in forward gear) is indicated on a decal on transmission case.
Page 145 SERVICE MANUAL NUMBER 24 MIE MODELS Hurth Transmissions On the Hurth 8° Down-Angle and V-Drive Transmissions the transmission identification plate indicates gear ratio, serial number and model. 73587 Typical Hurth Down-Angle Transmission Shown (V-Drive Identification Plate Similarly Located) Transmission Identification Plate On Velvet Drive In-Line and V-Drive Transmissions the gear ratio (in forward gear) is marked on transmission identification plate.
Page 146: Preparation
MIE MODELS SERVICE MANUAL NUMBER 24 Lubricants / Sealants / Adhesives Description Part Number Quicksilver 2-4-C Marine Lubricant With Teflon 92-825407A3 Quicksilver Liquid Neoprene 92-25711--3 Preparation 1. Disconnect battery cables from battery. 2. Remove instrument panel harness connector plug from engine harness receptacle after loosening clamp.
Page 147 SERVICE MANUAL NUMBER 24 MIE MODELS 1. Support engine with suitable sling through lifting eyes on engine. 75532 74510 Typical Rear Lifting Eye Front Lifting Eye 2. Remove front and rear engine mounting bolts. Retain hardware. 72638 Typical Mount Bolts or Lag Screws (with Washers) Slot Forward (If So Designed) 3.
Page 148: Installation And Alignment
MIE MODELS SERVICE MANUAL NUMBER 24 Installation and Alignment 1. Follow instructions “a” or “b”: a. Engine mount(s) or adjustment WAS NOT DISTURBED during engine service: Proceed to following Step 2. b. Engine mount(s) or adjustment WAS DISTURBED during engine service: IMPORTANT: Engine mounts must be adjusted, as explained in the following, to center mount adjustment and establish a uniform height on all mounts.
Page 149: Engine Final Alignment
SERVICE MANUAL NUMBER 24 MIE MODELS 2. Attach a suitable sling to lifting eyes on engine. Refer to “Removal” in this section for location of lifting eyes. IMPORTANT: Engine bed must position engine so that a minimum of 1/4 in. (6 mm) up-and-down adjustment still exists on all four mounts after performing final align- ment.
Page 150 MIE MODELS SERVICE MANUAL NUMBER 24 3. Check that coupling centerlines align, by butting propeller shaft coupler against trans- mission output flange. Shoulder on propeller shaft coupler should engage recess on transmission output flange face with no resistance. NOTE: Some propeller shaft couplers may not have a shoulder on mating face. On these installations, use a straight edge to check centerline alignment.
Page 151 SERVICE MANUAL NUMBER 24 MIE MODELS 5. If coupling centerlines are not aligned or if coupling faces are more than .003 in. (0.07 mm) out of parallel, adjust engine mounts as follows: a. TO ADJUST ENGINE UP OR DOWN: Loosen locking nut on mounts requiring adjustment and turn both front mount or rear mount adjusting nuts equally.
Page 152: Engine Connections
MIE MODELS SERVICE MANUAL NUMBER 24 10. Connect propeller shaft coupler to transmission output flange. Attach couplers together with bolts, lockwashers and nuts. Torque to 50 lb-ft (68 Nm). NOTE: If propeller shaft coupler has setscrews, the shaft should be dimpled at setscrew locations.
Page 153 SERVICE MANUAL NUMBER 24 MIE MODELS WARNING Avoid gasoline fire or explosion. Improper installation of brass fittings or plugs into fuel pump or fuel filter base can crack casting and/or cause a fuel leak. • Apply #592 Loctite Pipe Sealant with Teflon to threads of brass fitting or plug. DO NOT USE TEFLON TAPE.
Page 154 MIE MODELS SERVICE MANUAL NUMBER 24 5. Tighten all exhaust hose and/or exhaust tube clamps securely. 73961 Hose Clamps 6. On In-Line and Remote V-Drive: Connect and adjust Quicksilver shift cable(s) as out- lined following. IMPORTANT: When installing shift cables, be sure that cables are routed in such a way as to avoid sharp bends and/or contact with moving parts.
Page 155 SERVICE MANUAL NUMBER 24 MIE MODELS d. Locate center of remote control and control shift cable play (backlash), as follows: (1.) Check that remote control is in neutral position. (2.) Push in on control cable end with enough pressure to remove play and mark position “a”...
Page 156 MIE MODELS SERVICE MANUAL NUMBER 24 Reattach nut and washer to cable end guide stud. Tighten until contacts, then loosen one-half turn. k. Reattach nut and washer to cable barrel stud. Tighten until contacts. Tighten securely, but DO NOT OVERTIGHTEN. 50947 Rear Entry Single Station Installation In-Line And Remote V-Drive 50947...
Page 157 SERVICE MANUAL NUMBER 24 MIE MODELS 50946 Front Entry Single Station Installation In-Line And V-Drive 50946 Front Entry Dual Station Installation In-Line And V-Drive Cable End Guide Cable Barrel Cable Barrel Stud Elastic Stop Nut and Washer Spacer Cable End Guide Stud Elastic Stop Nut and Washer NOTE: For models equipped with a dual station shift bracket such as the one shown, refer to shift cable manufacturer’s instructions for adjusting the cable.
Page 158 MIE MODELS SERVICE MANUAL NUMBER 24 7. On 5000 series (8° Down Angle and V-Drive): Connect and adjust Quicksilver shift cable(s) as outlined following: For Left-Hand Propeller Shaft Rotation: Shift cable hookup at remote control must result in shift cable end guide moving in direction “A” when remote control handle is placed in forward position.
Page 159 SERVICE MANUAL NUMBER 24 MIE MODELS WARNING Avoid serious injury or property damage caused by improper shifting. Anchor stud for shift cable must be installed in the correct hole. a. Be certain anchor stud is installed in the front hole as shown in the illustration following.
Page 160 MIE MODELS SERVICE MANUAL NUMBER 24 g. Place remote control shift lever in gear and check position of transmission shift lever. Shift lever must be positioned in the desired detent hole. IMPORTANT: Transmission is fully in gear when shift lever comes to a stop in either direction.
Page 161 SERVICE MANUAL NUMBER 24 MIE MODELS 71780 71972 Typical Single Cable Installation - Rear Approach Cable End Guide Spacer (As Required) Elastic Stop Nut and Washer Bushing(s) Cable Barrel Stud Cable End Guide Stud 71897 50073 Typical Dual Cable Installation - Rear Approach Cable End Guide Spacer (As Required) Elastic Stop Nut and Washer...
Page 162 MIE MODELS SERVICE MANUAL NUMBER 24 8. Install throttle cable, or cables, following instructions “a,” “b” or “c”: a. On Models Equipped with Other Than Quicksilver Throttle Cables: Attach and adjust throttle cables referring to cable manufacturer’s instructions. b. On Carbureted Models Equipped with Quicksilver Throttle Cables: Connect and adjust throttle cable(s) as outlined following: (1.) Place remote control throttle lever(s) in idle position.
Page 163 SERVICE MANUAL NUMBER 24 MIE MODELS c. On EFI Models Equipped with Quicksilver Throttle Cables: Connect and adjust throttle cable(s) as outlined following: (1.) Place remote control handle in neutral idle position. (2.) Remove flame arrestor. (3.) Attach cable to throttle body following cable manufacturer’s instructions. (4.) Install cable end guide on throttle lever, then push cable barrel end lightly toward throttle lever end.
Page 164 MIE MODELS SERVICE MANUAL NUMBER 24 Attaching / Adjusting Reversed Attachment Morse Shift Cables 1. Disconnect battery cables from battery. 72608 MORSE MARINE PRODUCTS PART NUMBER A35627 NOTE: Each item includes: description, number required and part number. Cable Clip - 1 - A35531 Bracket -1 -B35762 Screw, Mach., Fill.
Page 165 SERVICE MANUAL NUMBER 24 MIE MODELS 4. Remove top transmission mounting bolt and lockwasher from left (valve) side of trans- mission; position bracket, replace bolt and lockwasher. 22457 Bolt Lock Washer 5. Fasten pivot pin securely through hole (not countersunk) in adaptor plate using lock- washer and nut.
Page 166 MIE MODELS SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 2B-24 90-861327--1 OCTOBER 1999...
Page 167 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES ENGINE Section 3A - 350 cid / 5.0L/ 305 cid / 5.7L Engines Table of Contents Torque Specifications ....3A-3 Valve Seat Repair .
Page 168 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Timing Chain and Sprocket ... 3A-78 Camshaft Bearings ....3A-82 Removal .
Page 169 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Torque Specifications Description lb-in. lb-ft Alternator Brace to Alternator Alternator Brace to Engine Alternator to Mounting Bracket Alternator Mounting Bracket Camshaft Sprocket Gear Carburetor or Throttle Body First Pass Connecting Rod Cap Final Pass (Angle...
Page 170 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Torque Specifications (Continued) Description lb-in. lb-ft Oil Baffle Nuts Oil Filter Adapter Bolt Oil Pan Drain Plug Oil Pan Corner Nut Oil Pan Nuts (5/16-18) Oil Pump Oil Pump Cover Power Steering Pump Brace to Block Power Steering Pump Bracket...
Page 171 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Special Tools KENT-MOORE SPECIAL TOOLS Kent-Moore Special Tools 29784 Little Mack Roseville, MI 48066 Phone: (313) 574-2332 Description Part Number Valve Spring Compressor (Head on) J5892 Valve Spring Compressor (Head off) J8062 Valve Spring Tester...
Page 172: General Specifications
5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Specifications General Specifications Engine Model 305 cid (5.0L) Displacement 305 cid (5.0 L) Bore 3.735 (94.89) Stroke 3.479 in. (88.39 mm) Firing Order 1-8-4-3-6-5-7-2 Compression Ratio 9.4:1 Heads Cast Iron...
Page 173: Engine Specifications
SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Engine Specifications NOTICE Unit Of Measurement: Inches (Millimeters) CYLINDER BORE Engine 305 cid (5.0L) 350 cid (5.7L) 3.7350-3.7384 4.00-4.001 Diameter (94.881-94.958) (101.618-101.643) Production 0.001 (0.025) Max Out of Round Service 0.002 (0.05) Max...
Page 174 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 PISTON PIN Diameter 0.9269-0.9270 (23.545-23.548) Production 0.0005-0.0009 (0.013-0.023) Clearance Service Limit 0.0005-0.00098 (0.013-0.025) Max Fit in Rod 0.00082-0.00157 (0.021-0.040) Interference CRANKSHAFT Engine 305 cid (5.0L) 350 cid (5.7L) Main Journal Diameter No.1...
Page 175 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES VALVE SYSTEM Engine 305 cid (5.0L) 350 CID (5.7L) Lifter Type Roller Hydraulic Rocker Arm Ratio 1.50 to 1 Intake 0.2744-.2783 (6.97-7.07) Valve Lift Exhaust 0.2834-.2874 (7.20-7.30) Valve Lash 1 Turn Down from Zero Lash (Intake and Exhaust)
Page 176 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 CAMSHAFT AND DRIVE Engine 305 cid (5.0L) 350 cid (5.7L) Journal Diameter 1.8677-1.8661 (47.440-47.490) Journal Out Of Round 0.001 (0.025) Maximum Camshaft Runout 0.0026 (0.06) Maximum Timing Chain Deflection 0.43 (11) Maximum FLYWHEEL...
Page 177 Engine Identification The Mercury MerCruiser Model can be determined by looking at the last two letters of the engine code stamped into the cylinder block. This code number is stamped on all Mercury MerCruiser power packages and replacement partial engines, but not replacement cylinder block assemblies.
Page 178 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Engine Rotation Engine rotation terminology at times has caused confusion. To clarify, engine rotation is determined by observing flywheel rotation from the rear (transmission or stern drive end) of the engine looking forward (water pump end).
Page 179 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES CAUTION Avoid rapid and severe camshaft and fuel pump push rod wear that could result in engine damage. Always use the fuel pump push rod specified for use with the cast iron or steel camshaft in your engine.
Page 180 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Some of the oil, after leaving the oil cooler and/or filter, is routed to the No. 5 crankshaft main bearing. The remainder of the oil is routed to the main oil gallery, which is located directly above the camshaft and runs the entire length of the block.
Page 181: Bearing Failures
SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Bearing Failures 70436 Scratched By Dirt Scratches Dirt Imbedded In Bearing Material 70436 Tapered Journal Overlay Gone From Entire Surface 70436 Lack Of Oil Overlay Worn Off 70436 Radius Ride Worn Area...
Page 182: Piston Failures
NOTE: Engine failures that result from the foregoing conditions are beyond the control of Mercury MerCruiser. No warranty will apply to failures that occur under these conditions. Index Page 3A-16...
Page 183 6. Inadequate cooling of engine due to deterioration of cooling system. NOTE: Engine failures, that result from the foregoing conditions are beyond the control of Mercury MerCruiser. No warranty will apply to failures that occur under these conditions. 72425 Detonation Damage...
Page 184: Engine Mounts
5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Engine Mounts 72317 Front Mount - All MCM (Sterndrive) Models 72318 Rear Mount / Flywheel Housing - All MCM (Sterndrive) Models 72319 Front Mount Assembly - All MIE Models Index Page 3A-18 90-861327--1 OCTOBER 1999...
Page 185 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Engine Mounts (Continued) 73055 Rear Mount Assembly - Most MIE Models 73056 Rear Mount Assembly - MIE Models with Velvet Drive In-Line Transmission Index 90-861327--1 OCTOBER 1999 Page 3A-19...
Page 186: Rocker Arm Cover
5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Rocker Arm Cover Removal NOTE: It may be necessary to remove exhaust manifold before removing rocker arm cover. Refer to SECTION 7B for exhaust manifold removal. 1.
Page 187 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Intake Manifold Removal 1. Drain engine cooling system. 2. Disconnect hoses from thermostat housing. 3. Disconnect electrical leads interfering with removal. 4. Disconnect crankcase ventilation hoses from rocker arm covers. 5.
Page 188 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Installation IMPORTANT: DO NOT get Quicksilver RTV Sealer into oil sending unit hole at rear of engine. 1. Apply a 3/16 in. (5 mm) wide bead of Quicksilver RTV Sealer to engine block as shown. Extend sealer 1/2 in.
Page 189 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES 7. Connect crankcase ventilation hose(s). 8. Install distributor. Position rotor and housing to align with marks made during removal, then install distributor cap. 9. Install other ignition components and reconnect wires. 10.
Page 190: Valve Adjustment
5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Valve Adjustment Engine Stopped With valve cover removed, adjust valves when lifter is on low part of camshaft lobe. 1. Crank engine with starter or turn over in normal direction of rotation until mark on torsion- al damper lines up with center “0”...
Page 191 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Engine Operating Following procedure is performed with engine operating: 1. Check engine for normal operating temperature. 2. Remove rocker arm covers and install rocker stoppers as shown. 72301 Rocker Stoppers (91-66273) Rocker Arm Nuts...
Page 192 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Hydraulic Valve Lifters 72031 Roller Lifter Push Rod Seat Retainer Push Rod Seat Metering Valve Plunger Check Ball Check Ball Spring Check Ball Retainer Plunger Spring Lifter Body Hydraulic valve lifters require little attention.
Page 193 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES 4. Intermittent clicking. Probable causes are: a. A microscopic piece of dirt momentarily caught between ball seat and check valve ball. b. In rare cases, ball may be out of round or have a flat spot. c.
Page 194 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Cleaning and Inspection 1. Thoroughly clean all parts in cleaning solvent and inspect them carefully. If any parts are damaged or worn, entire lifter assembly should be replaced. 2.
Page 195 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Valve Stem Oil Seal / Valve Spring Removal - Head Installed 1. Remove rocker arm cover. 2. Remove spark plug of affected cylinder. 3. Remove rocker arm assembly. 4.
Page 196 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Valve Assembly (Exploded View) 72331 Intake Exhaust Valve Locks Retainer Rotator Valve Guide Oil Seal Oil Shield Valve Stem Oil Seal Inner Spring Outer Spring 10 - Intake Valve 11 - Exhaust Valve...
Page 197 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES 5. Install valve locks (Quicksilver Needle Bearing Assembly Lubricant may be used to hold them in place) and slowly release tool, making sure locks seat properly in upper grooves of valve stem.
Page 198 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Installation CAUTION When using ribbed stainless steel head gaskets, apply a thin coating of Quicksilver Perfect Seal to both sides of gasket. Too much sealer may hold gasket away from head or block causing leakage.
Page 199: Cylinder Head And Valve Conditioning
SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES 9. Follow procedures in SECTION 6A or 6B of this manual: Seawater Cooled Models: Provide for adequate water supply to seawater pickup (see SECTION 6A). Closed Cooled Models: Refill closed cooling section (see SECTION 6B), and provide ade- quate water supply to seawater pickup.
Page 200 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Cleaning and Inspection 1. Clean push rods and rocker arm assemblies. 2. Clean carbon from valves using a wire wheel. 3. Clean gasket material from cylinder head mating surfaces. 4.
Page 201 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES IMPORTANT: Cylinder head surfaces should be resurfaced if warped more than specified to provide proper alignment. 9. Inspect valves for burned heads, cracked faces or damaged stems. IMPORTANT: Excessive valve stem to bore clearance will cause excessive oil con- sumption and possible valve breakage.
Page 202: Valve Guide Bore Repair
5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Valve Guide Bore Repair IMPORTANT: Measure valve stem diameter of both the intake and exhaust valve, as valve stem diameter may or may not be the same for both valves. If .015 in.
Page 203 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Rocker Arm Stud Replacement 1. Replace worn or loose rocker arm studs with oversize studs. 2. Use rocker arm stud remover to partially remove old stud as follows: a.
Page 204: Valve Seat Repair
5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Valve Seat Repair Valve seat reconditioning is very important, since seating of valves must be perfect for engine to deliver maximum power and performance. Another important factor is valve head cooling. Good contact between each valve and its seat in valve head is important to ensure that heat will be properly dispersed.
Page 205 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Valve Grinding Valves that are pitted must be refaced to the proper angle. Valve stems that show excessive warp or wear, must be replaced. When a warped valve head is refaced, a knife edge will be ground on part or all of the valve head due to the amount of metal that must be removed to completely reface.
Page 206 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 6. While compressing valve spring install oil seal in lower groove of valve stem. Ensure seal is not twisted. A light coating of oil will help prevent twisting. 72333 Valve Spring Compressor (J-8062) 7.
Page 207 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES IMPORTANT: If measurement exceeds specified height, install a valve spring shim and re- check. DO NOT shim valve springs to give an installed height less than the minimum speci- fied.
Page 208: All Engines
5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Crankcase Oil Dipstick Specifications All Engines 1/2 (13) 1/2 (13) 13-29/32 (353) (787) FULL FULL 15-19/32 33-1/4 (396) (845) 3/4 (19) 15/16 (24) 72341 1/2 (13) 1/2 (13) 14-25/32 32 (814)
Page 209 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Crankcase Oil Dipstick Specifications (Continued) 14 (349) 13 (330) 15 1/2 (396) 15 1/2 (396) (15) (22) OP. RANGE OP. RANGE 31 (787) 33 1/2 (851) 33 1/4 (845) 35 1/4 (895) (19)
Page 210: Oil Pan
5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Oil Pan Removal 1. Drain crankcase oil. 2. If necessary, disconnect outlet hose from seawater pump. 3. Remove dipstick and tube. On MIE models, be careful not to disturb orientation of banjo fitting on bottom of pan.
Page 211 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES 2. Install oil pan gasket in position as shown. NOTE: A one-piece oil pan gasket may be re-used if it is still pliable and is not cracked, torn or otherwise damaged.
Page 212 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Tighten all connections on banjo fitting at this time. Torque banjo fitting bolt to 180 lb-in. (20 Nm). Tighten dipstick tube and plug securely. 71860 76386 Typical Dipstick Styles Gage Clamp (Secured by Manifold Screw)
Page 213: Oil Pump
SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Oil Pump The oil pump consists of two gears and a pressure regulator valve enclosed in a two-piece housing. It is only available as an assembly. The oil pump is driven by the distributor shaft, which is driven by a helical gear on camshaft.
Page 214 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Removal 1. Remove oil pan as outlined. 2. Remove gasket carefully as the one-piece gasket for the oil pan may be reused if still pliable and not cracked, torn or otherwise damaged. 3.
Page 215 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Reassembly CAUTION Be careful of twisting, shearing or collapsing pipe while installing in pump. Pickup screen must be parallel to oil pan bottom when oil pump is installed. 1.
Page 216: Torsional Damper
5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Torsional Damper Removal 1. Remove drive belts. 2. Remove drive pulley, 3. Remove torsional damper retaining bolt. IMPORTANT: Do not use a universal claw type puller to remove torsional damper (in next step) as outside ring of torsional damper is bonded in rubber to the hub and use of claw type puller may break the bond.
Page 217 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES IMPORTANT: Be sure to install threaded rod in crankshaft at least 1/2 in. (13 mm) to prevent damage to threads. b. Install plate, thrust bearing, washer and nut on rod. c.
Page 218 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Crankcase Front Cover Oil Seal Oil Seal Replacement (Without Removing Front Cover) REMOVAL 1. Remove torsional damper. 2. Pry seal out of cover from the front with a large screwdriver. Be careful not to distort front cover or damage crankshaft.
Page 219: Crankcase Front Cover
SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Crankcase Front Cover Removal 1. Remove engine from boat if necessary to gain access to cover. 2. Remove torsional damper and oil pan. 3. Remove water circulating pump. IMPORTANT: Crankcase front cover is not reusable per G.M.
Page 220 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 4. Install oil pan and torsional damper as outlined. 5. Install water circulating pump. 6. Reinstall engine in boat. 7. Fill crankcase with engine oil. 8. Follow procedures in SECTION 6A or 6B of this manual: Seawater Cooled Models: Provide for adequate water supply to seawater pickup (see SECTION 6A).
Page 221 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Flywheel Removal 1. Remove engine from boat. 2. Remove transmission, if equipped. 3. Remove flywheel housing and related parts. 4. Remove MCM coupler or MIE drive plate. 5.
Page 222 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Cleaning and Inspection 1. Inspect splines in drive plate or coupler for wear. 2. Check flywheel ring gear for worn and missing teeth. 3. Clean mating surfaces of flywheel and crankshaft. Remove any burrs. Mating surfaces must be clean bare metal.
Page 223: Rear Main Oil Seal
SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES IMPORTANT: Insert three rubber bumpers in Alpha coupler before installation on fly- wheel. 3. Insert three rubber bumpers in Alpha coupler before installation on flywheel. 72354 Typical Rubber Bumper (Alpha Coupler Only) Coupler...
Page 224 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Cleaning and Inspection 1. Clean crankshaft seal running surface. 2. Clean the seal retainer bore. Installation 1. Apply a thin coat of clean engine oil to the bore of the seal retainer. 2.
Page 225 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Rear Main Oil Seal Retainer The rear main oil seal retainer can only be replaced with the oil pan removed. Removal 1. Remove oil pan. 2. Remove oil seal retainer fasteners. 3.
Page 226: Main Bearings
5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Main Bearings IMPORTANT: Before removing main bearing caps or connecting rod caps, mark them for reassembly in their original locations. Main bearings are of the precision insert type and do not use shims for adjustment. If clearances are found to be excessive, a new bearing, both upper and lower halves, will be required.
Page 227 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES 3. Install the bearing cap and evenly torque the retaining bolts to specifications. Bearing cap MUST be torqued to specification to ensure proper reading. Variations in torque af- fect the compression of the plastic gauge.
Page 228 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 9. Measure crankshaft end play (see “Specifications”) by forcing the crankshaft to the ex- treme front position. Measure at the front end of the rear main bearing with a feeler gauge as shown.
Page 229 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES WITHOUT CRANKSHAFT REMOVED 1. Remove oil pan, oil pump and spark plugs. 2. Remove cap on main bearing requiring replacement. 3. Remove bearing from cap. 4. Install main bearing remover/installer in oil hole in crankshaft journal. If such a tool is not available, a cotter pin may be bent, as shown, and used.
Page 230: Connecting Rod Bearings
5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Connecting Rod Bearings Connecting rod bearings are of the precision insert type and do not use shims for adjust- ment. DO NOT FILE RODS OR ROD CAPS. If clearances are found to be excessive, a new bearing will be required.
Page 231 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES c. Install the bearing in the connecting rod and cap. d. Install the bearing cap. Bearing cap MUST be torqued to specification in order to ensure proper reading. Variations in torque affect the compression of the plastic gauge.
Page 232 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Connecting Rod / Piston Assembly Removal 1. Remove oil pan and dipstick tube. 2. Remove baffle and oil pump. 3. Remove distributor and intake manifold. 4. Remove cylinder heads. IMPORTANT: Before ridge and/or deposits are removed, turn crankshaft until piston is at bottom of stroke and place a cloth on top of piston to collect cuttings.
Page 233 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Disassembly Disassemble piston from connecting rod using piston pin remover as shown. Follow instruc- tions supplied with kit. 72365 Piston Pin Remover (J-24086-B) Arched Base Piston Connecting Rod Rod Support Cleaning and Inspection...
Page 234 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 5. Slip outer surface of a new top and second compression ring into respective piston ring- groove and roll ring entirely around the groove to make sure that ring is free as shown. If binding occurs at any point, determine cause.
Page 235 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Reassembly IMPORTANT: When reassembling pistons and connecting rods, the following must be kept in mind. • Piston and pin are machine fitted to each other and must remain together as a matched set.
Page 236 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 1. Assemble piston to connecting rod using piston pin remover as shown. Follow instruc- tions supplied with kit. 72371 Piston Pin Remover (J-24086-B) 2. Once assembled, check piston for freedom of movement (back and forth and up and down) on connecting rod.
Page 237 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES a. Install oil ring spacer in groove and insert anti- rotation tang in oil hole. b. Hold spacer ends butted and install lower steel oil ring rail with gap properly located. c.
Page 238 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 8. Hold ring compressor firmly against cylinder block until all piston rings have entered cyl- inder bore. IMPORTANT: Be sure to install new pistons in same cylinders for which they were fitted, and used pistons in same cylinder from which they were removed.
Page 239 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Crankshaft Removal 1. Remove engine from boat. 2. Drain crankcase oil. 3. Remove starter. 76489 Starter Mounting Bolts 4. Remove flywheel housing. 5. Remove drive coupler/plate and flywheel. 76490 Flywheel Bolts...
Page 240 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 12. Remove timing chain gear cover. 76491 Timing Chain Gear Cover 13. Remove timing chain. 14. Turn crankshaft to align timing mark with camshaft mark. 15. Remove camshaft sprocket or gear. 76488 16.
Page 241 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES 19. Remove main bearing caps and carefully lift crankshaft out of cylinder block. 76492 Connecting Rod Bearing Caps Main Bearing Cap Crankshaft 20. If new main and/or connecting rod bearings are to be installed, remove main bearing inserts from cylinder block and bearing caps, and/or connecting rod bearing inserts from connecting rod and caps.
Page 242 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Installation 1. Remove timing sprocket or gear from old crankshaft and reinstall on new crankshaft as outlined. 2. On jackshaft models, if old pilot bushing is to be reused, bushing can be removed without damage.
Page 243 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES 15. Install timing chain and sprocket or gear on camshaft -align marks with crankshaft. 16. Install timing chain/gear cover. 17. Install oil pump and baffle. 18. Install dipstick tube and oil pan. 19.
Page 244 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Cleaning and Inspection 1. Clean all parts in solvent and dry with compressed air. 2. Inspect timing chain for wear and damage. 3. Inspect sprockets for wear and damage. 4.
Page 245 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES 5. The deflection is the difference between these two measurements. If the deflection ex- ceeds 3/4 in. (19 mm), timing chain should be replaced. 72376 Reference Point Camshaft Measuring Lobe Lift NOTE: Procedure is similar to checking valve timing.
Page 246 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Removal 1. Remove valve lifters. 2. Remove crankcase front cover. 3. Remove fuel pump and fuel pump push rod. 4. Remove camshaft as follows: a. Remove timing chain and sprocket or timing gears as outlined. On the 5.7L engine only, remove camshaft thrust plate.
Page 247 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Camshaft Bearings Removal Camshaft bearings can be replaced while engine is disassembled for overhaul or without complete disassembly. To replace bearings without complete disassembly, fasten connect- ing rods against sides of engine so that they will not interfere while replacing camshaft bear- ings.
Page 248 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Cleaning and Inspection Clean camshaft bearing bores in cylinder block with solvent and blow out with compressed air. Be sure grooves and drilled oil passages are clean. Installation Front and rear bearings must be installed last as pilot will not fit into bearing bores if bearings are installed.
Page 249: Cylinder Block
SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Cylinder Block Cleaning and Inspection 1. Remove all engine components. 2. Wash cylinder block thoroughly in cleaning solvent. 3. Clean all gasket surfaces. 4. Remove oil gallery plugs. 5.
Page 250 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 10. Check cylinder head gasket surfaces for warp with a machinist’s straight-edge and a feeler gauge. Take measurements diagonally across surfaces (both ways) and straight down center. If surfaces are warped more than .003 in. (0.07 mm) in a 6 in. area or .007 in.
Page 251 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES CYLINDER HONING 1. Follow hone manufacturer’s recommendations for use of hone and cleaning and lubrica- tion during honing. 2. Occasionally, during the honing operation, thoroughly clean cylinder bore and check piston for correct fit in cylinder.
Page 252 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 b. Measure piston diameter at skirt across center line of piston pin as shown. 72624 c. Subtract piston diameter from cylinder bore diameter to determine piston-to-bore clearance.
Page 253 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES Oil Filter By-Pass Valve and Adaptor Assembly 72389 Without Remote Oil Filter 72390 With Remote Oil Filter Fiber Valve IMPORTANT: Oil by-pass valve and adaptor assembly should be inspected whenever engine is disassembled for major repair or whenever inadequate oil filtration is sus- pected.
Page 254 5.0l / 305 cid / 5.7l / 350 cid ENGINES SERVICE MANUAL NUMBER 24 Removal 1. Remove oil filter (on engines with block mounted filter) or cylinder block adaptor (on engines with remote oil filter). 2. Remove by-pass valve and adaptor assembly. Cleaning and Inspection 1.
Page 255 SERVICE MANUAL NUMBER 24 5.0l / 305 cid / 5.7l / 350 cid ENGINES THIS PAGE IS INTENTIONALLY BLANK Index 90-861327--1 OCTOBER 1999 Page 3A-89...
Page 256 SERVICE MANUAL NUMBER 24 STARTING SYSTEM ELECTRICAL SYSTEMS Section 4A - Starting System Table of Contents Identification ......4A-2 Exploded View .
Page 257 STARTING SYSTEM SERVICE MANUAL NUMBER 24 Identification 75820 Permanent Magnet Gear Reduction (PG260F1) Starter 76505 Delco 14MT Direct Drive Starter Replacement Parts Warning WARNING Electrical, ignition and fuel system components comply with U.S. Coast Guard Rules and Regulations to minimize risks of fire and explosion. Use of replacement electrical, ignition or fuel system components, which do not comply with these rules and regulations, could result in a fire or explosion hazard and should be avoided.
Page 258 SERVICE MANUAL NUMBER 24 STARTING SYSTEM Typical Starting System Components 72930 Ignition Switch 20 Amp Fuse Starter Slave Solenoid Circuit Breaker Starter Motor Wire Junction Neutral Safety Switch 90 Amp. Fuse Engine Ground (-) Index 90-861327--1 OCTOBER 1999 Page 4A-3...
Page 259: Positive Current Flow
STARTING SYSTEM SERVICE MANUAL NUMBER 24 Positive Current Flow This is a general description of the positive current flow from the battery through the system until the starter motor cranks. NOTE: Check that all connections are tight and have the required resistance. •...
Page 260 SERVICE MANUAL NUMBER 24 STARTING SYSTEM MULTIPLE EFI ENGINE BATTERY PRECAUTIONS Situation Alternators: Alternators are designed to charge the battery that supplies electrical power to the engine that the alternator is mounted on. When batteries for two different engines are connected, one alternator will supply all of the charging current for both batteries.
Page 261 STARTING SYSTEM SERVICE MANUAL NUMBER 24 Maintenance WARNING DO NOT use jumper cables and a booster battery to start engine. DO NOT recharge a weak battery in the boat. Remove battery and recharge in a well ventilated area away from fuel vapors, sparks or flames. WARNING Batteries contain acid which can cause severe burns.
Page 262 SERVICE MANUAL NUMBER 24 STARTING SYSTEM Testing CAUTION Test battery in well ventilated area as gases given off by battery are hazardous. A strong battery must be maintained. If battery shows less than 9.5 volts when under starting load, (at 80° F or 27° C) it should be recharged. Check with DC voltmeter. 76498 Voltmeter Battery...
Page 263: Charging Guide
STARTING SYSTEM SERVICE MANUAL NUMBER 24 Storage 1. Remove battery and clean exterior. 2. Check fluid level and fill if low. 3. Cover terminals and bolts with light coat of grease. 4. Set battery on wood or in carton; store in cool, dry place. 5.
Page 264: Standard Starter Slave Solenoid
SERVICE MANUAL NUMBER 24 STARTING SYSTEM How Temperature Affects Battery Power POWER (WATTS) AVAILABLE POWER (WATTS) REQUIRED 100% 80° F(27° C) 100% 165% 32° F(0° C) 250% 0° F(-18° C) 350% -20° F(-29° C) 74310 Standard Starter Slave Solenoid Identification 76517 Index 90-861327--1 OCTOBER 1999...
Page 265 STARTING SYSTEM SERVICE MANUAL NUMBER 24 Testing / Replacement 1. Using continuity meter, connect test leads as shown, and connect 12 volt battery with jumper leads as shown. 72630 2. If no meter movement is present, replace solenoid. Testing Starter Motor Voltage Always test the voltage at the starter motor to ensure that it is getting at least 9.5 volts during cranking.
Page 266 SERVICE MANUAL NUMBER 24 STARTING SYSTEM Voltage Drop In Starting System This test should be done anytime a voltage drop is suspected. 1. With a fully charged battery, connect volmeter positive (+) lead to the battery positive (+) post. 2. Connect the voltmeter negative (–) lead to the starter solenoid terminal where the posi- tive (+) battery cable connects.
Page 267 STARTING SYSTEM SERVICE MANUAL NUMBER 24 Delco 14MT Direct Drive Starter Specifications Starter Specifications Direct Drive Starter Motor Engine Brush No Load Test Delco Iden- Rotation Spring tification Tension Oz. Min. Max. Min. Max. Number Volts (Grams) Amps Amps 56-105 10455602 10.6 5400...
Page 268 SERVICE MANUAL NUMBER 24 STARTING SYSTEM Exploded View 72806 End Housing 18 - Screw/Stud End Housing Bushing 19 - Insulator Holder - Field Frame Brush Thrust Collar 20 - Field Frame Brush - Ground Brush Retaining Ring - Pinion Stop Collar 21 - Field Frame Brush Pinion Stop Collar...
Page 269: Installation
STARTING SYSTEM SERVICE MANUAL NUMBER 24 Solenoid Switch The solenoid switch can be removed and replaced if defective. Removal 1. Remove starter motor as outlined. 2. Remove screw from field coil connector and solenoid attaching screws. 3. Twist solenoid to disengage tab, and remove. Installation 1.
Page 270 SERVICE MANUAL NUMBER 24 STARTING SYSTEM Checking Pinion Clearance Pinion clearance must be checked as follows after reassembly of motor to insure proper adjustment. 1. Disconnect motor field coil connector from solenoid motor terminal and insulate it care- fully. 72631 Motor Field Coil Connector 2.
Page 271 STARTING SYSTEM SERVICE MANUAL NUMBER 24 6. If clearance is not within limits of .010-.140 in. (0.25-3.5 mm), it may indicate excessive wear of solenoid linkage shift lever yoke buttons or improper assembly of shift lever mechanism. Check for proper assembly, and recheck gap. If still excessive, replace worn or defective parts, since no provision is made for adjusting pinion clearance.
Page 272 SERVICE MANUAL NUMBER 24 STARTING SYSTEM Installation 1. Place starter motor in position and install mounting bolts. Torque bolts to 50 lb-ft (68 Nm). 2. Fasten wires. 3. Coat solenoid terminal connections with Quicksilver Liquid Neoprene. 4. Place rubber boot over positive battery cable connection. 72637 Positive (+) Battery Cable Rubber Boot...
Page 273: Delco Pg260F1 Starter
STARTING SYSTEM SERVICE MANUAL NUMBER 24 Delco PG260F1 Starter Specifications Starter Specifications PG260F1 Starter Motor MerCruiser Part Number 50-807904 Delco No Load Test Identifi- Engine Rota- Volts Min. Max. cation tion Min. rpm Max. rpm Amps Number 9000839 - 11.5...
Page 274: Exploded View
SERVICE MANUAL NUMBER 24 STARTING SYSTEM Exploded View 74270 Screw (2) 12 - Collar End Frame and Bearing 13 - Retaining Ring Brush With Holder 14 - Trust Collar Armature 15 - Drive Housing Field Frame (With Permanent Magnets) 16 - Washer 17 - Solenoid...
Page 275: Motor
STARTING SYSTEM SERVICE MANUAL NUMBER 24 Motor Removal WARNING Disconnect battery cables at battery before removing starter. 1. Disconnect battery cables from battery. 2. Disconnect wires from solenoid terminals. IMPORTANT: Some starter motors may use a special mounting shim for gaining fly- wheel clearance.
Page 276 SERVICE MANUAL NUMBER 24 STARTING SYSTEM 2. Remove armature and field frame from drive housing. NOTE: Permanent magnets inside field frame will be holding armature in place. 74270 End Frame and Bearing Screws (2) Brush Holder Armature Field Frame 3. Remove shield and washer from drive housing. 74038 Shield Washer...
Page 277 STARTING SYSTEM SERVICE MANUAL NUMBER 24 4. Remove the three screws retaining the solenoid. Remove solenoid from drive housing. 74036 Drive Housing Solenoid Screws (3) 5. Remove drive and associated parts from drive housing. 75821 74035 Drive Housing Drive 6. Remove solenoid arm,metal disc and rubber grommet from the drive housing. 75821 Rubber Grommet Metal Disc...
Page 278 SERVICE MANUAL NUMBER 24 STARTING SYSTEM 7. Remove thrust collar, retaining ring and collar from planetary shaft with drive. 75821 Thrust Collar Retaining Ring (Inside Collar) Collar Planetary Shaft and Drive 8. Remove drive and gear from planetary shaft. 74087 Typical Gear Shaft Assembly...
Page 279: Cleaning And Inspection
STARTING SYSTEM SERVICE MANUAL NUMBER 24 Cleaning and Inspection IMPORTANT: Do not use grease dissolving solvents to clean electrical components, planetary gears or drive. Solvent will damage insulation and wash the lubricant out of the drive and gears. Use clean rags and compressed air to clean components. 1.
Page 280 SERVICE MANUAL NUMBER 24 STARTING SYSTEM e. Position snap ring on upper end of shaft and hold in place with block of wood. Strike wood block with hammer, thus forcing snap ring over end of shaft. Slide snap ring down into groove. 72073 Snap Ring Groove...
Page 281 STARTING SYSTEM SERVICE MANUAL NUMBER 24 3. Install the planetary gears on planetary gear shaft assembly. 4. Install solenoid arm, metal disc and rubber grommet in the drive housing. NOTE: Solenoid arm is designed to fit only one way. Do not use force. 75821 Rubber Grommet Metal Disc...
Page 282 SERVICE MANUAL NUMBER 24 STARTING SYSTEM 6. Attach solenoid arm to solenoid. Place solenoid in drive housing and tighten screws. 74036 Drive Housing Solenoid Screw (3) Solenoid Arm 7. Install washer and shield in drive housing. 74038 75821 Washer Shield Drive Housing 8.
Page 283: Checking Pinion Clearance
STARTING SYSTEM SERVICE MANUAL NUMBER 24 10. Install long screws and brush lead. Tighten fasteners securely. 75821 End Frame Field Frame Drive Housing Long Screws Brush Lead Checking Pinion Clearance Pinion clearance must be checked after reassembly of starter motor. 1.
Page 284: Installation
SERVICE MANUAL NUMBER 24 STARTING SYSTEM 6. If clearance is not within limits of .010-.160 in. (0.25-4.00 mm), it may indicate excessive wear of solenoid linkage, shift lever yoke, or improper assembly of shift lever mecha- nism. Replace solenoid switch, since no provision is made for adjusting pinion clear- ance.
Page 285 STARTING SYSTEM SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 4A-30 90-861327--1 OCTOBER 1999...
Page 286 IGNITION SYSTEM SERVICE MANUAL NUMBER 24 ELECTRICAL SYSTEMS Section 4B - Ignition System Table of Contents Ignition Control System Components 4B-2 Mercury Marine Distributor ... 4B-17 Replacement Parts Warning ..4B-2 Description .
Page 287: Ignition Control System Components
Ignition Control System Components Replacement Parts Warning WARNING Electrical, ignition and fuel system components on your MerCruiser are designed and manufactured to comply with U.S. Coast Guard Rules and Regulations to mini- mize risks of fire and explosion. Use of replacement electrical, ignition or fuel system components, which do not comply with these rules and regulations, could result in a fire or explosion hazard and should be avoided.
Page 288: Efi System Maintenance Precautions
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 EFI System Maintenance Precautions WARNING Avoid Injury or Electrical System Damage: Always disconnect battery cables from battery before working around electrical system components. See CAUTION following: CAUTION Avoid damage to the EFI electrical system components: Refer to the following precautions when working on or around the EFI electrical harness, or when adding other electrical accessories: •...
Page 289: Ignition System Specifications
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Ignition System Specifications Description Specification Ignition Timing EFI / MPI Models 8° BTDC Carbureted Models 10° BTDC Firing Order 1-8-4-3-6-5-7-2 Distributor Description GM EST Mercury Distributor Part Number 805222A1 805185A36 Coil Description GM EST Mercury Coil Part Number 392-7803A4...
Page 290: Timing
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Timing Thunderbolt V Models 1. Connect timing light to number 1 spark plug wire. 2. Connect a shop tachometer to the engine. IMPORTANT: Before starting the engine, connect a jumper wire from the ignition tim- ing lead to a good ground.
Page 291: Efi / Mpi Models
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 EFI / MPI Models 1. Connect timing light to number 1 spark plug wire. 2. Start engine and run at 1300 rpm until it reaches normal operating temperature. 3. Stop engine and connect the scan tool or timing tool to the DLC connector on the EFI/ MPI wiring harness.
Page 292 IGNITION SYSTEM SERVICE MANUAL NUMBER 24 2. Inspect each plug individually for badly worn electrodes, glazed, broken or blistered porcelain and replace where necessary. 72734 Porcelain Insulator Insulator - Cracks Often Occur at This Point Shell Proper Gap Side Electrode Center Electrode (When Adjusting Gap - DO NOT Bend) Replacing 1.
Page 293: Spark Plug Wires
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Spark Plug Wires IMPORTANT: Proper positioning in spark plug wire supports is important to prevent cross-firing. Inspection 1. Visually inspect spark plug wires and coil wire for damage, such as cracks. 2. Visually inspect spark plug boots for damage. NOTE: Use care when removing spark plug wires and boots from spark plugs.
Page 294: Ignition Coil
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 d. Push end of high tension wire into coil tower. Position boot over coil tower and wipe off excess insulating compound. 76470 Distributor Coil Wire Terminal NOTE: Make sure boot does not come off of tower due to hydraulic air pressure inside boot. Ignition Coil NOTICE Refer to “Service Precautions”...
Page 295 IGNITION SYSTEM SERVICE MANUAL NUMBER 24 RESISTANCE TEST 1. Check the resistance of the coil with an ohmmeter, as follows: a. Connect an ohmmeter as shown for Test 1. Using the high scale the reading should be infinite. If not, replace the ignition coil. b.
Page 296: Carbureted Engines - Thunderbolt V Ignition
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Carbureted Engines - Thunderbolt V Ignition Spark Control Features IDLE SPEED SPARK CONTROL The Ignition Module controls ignition timing to maintain a calibrated idle speed by making small spark advance adjustments. This feature is only active between 400-700 rpm. ACCELERATION SPARK ADVANCE When accelerating, the Ignition Module may add more spark advance to the “Base Spark Timing Curve.”...
Page 297: Circuit Description
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 KNOCK RETARD SPARK CONTROL The knock control feature helps provide protection from harmful detonation. Knock control is handled by the Knock Control Module. This module receives a signal from a sensor that is mounted on the engine block. The Knock Control Module works in conjunction with the Ignition Module to retard the timing if spark knock is present.
Page 298: Thunderbolt V Spark Control Graph
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Thunderbolt V Spark Control Graph IMPORTANT: The graph below shows the typical advance ranges for a Thunderbolt V Ignition Control Module. The numbers plotted on the graph are not representative of any particular model. It is only presented to provide an understanding of how the system functions.
Page 299 IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Ignition System Wiring Diagram TO ENGINE HARNESS TO DISTRIBUTOR KNOCK IGNITION CONTROL CONTROL MODULE MODULE 75456 NOTE: Alpha Models Are Equipped With A Shift Cut-Out Switch. 305 and 350 cid Bravo Models Will Have Two BLACK Leads Connected Together. Knock Sensor Wire Water Temperature Switch (For Audio Warning) (Pin H)
Page 300 IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Thunderbolt V Ignition Module REMOVAL 1. Unplug wiring harness connectors from Ignition Module. 2. Remove fasteners and hardware retaining Ignition Module to exhaust elbow. 3. Remove module. CLEANING AND INSPECTION 1. Check that terminals of wiring harness connector are clean and free of corrosion. INSTALLATION 1.
Page 301 IGNITION SYSTEM SERVICE MANUAL NUMBER 24 TESTING KNOCK MODULE AND KNOCK SENSOR NOTE: A digital volt-ohmmeter (DVOM) and an unpowered test light (low power test light - 300mA or less) are needed to conduct the following test. WARNING Avoid fire or explosion. Ensure that engine compartment is well ventilated and gas- oline vapors are not present when performing electrical tests inside the engine compartment.
Page 302 IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Mercury Marine Distributor Description This distributor is used on carbureted models with Thunderbolt V ignition system and EFI/ MPI MEFI 3 ECM models, except Black Scorpion. The Black Scorpion models use the Delco EST ignition system. Exploded View 00000 Distributor Cap...
Page 303: Installation
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Distributor Cap Removal 1. Loosen the distributor cap retaining screws. 2. Lift cap away from distributor. Cleaning and Inspection 1. Check cap contacts for excessive burning or corrosion. 2. Check center contact for damage. 3.
Page 304 IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Rotor / Sensor Wheel Removal 1. Remove distributor rotor / sensor wheel assembly from distributor shaft using two flat blade screwdrivers. Position the screwdrivers opposite each other with the blade tips contacting the shaft. A downward push on both screwdriver handles at the same time will pry off rotor / sensor wheel assembly.
Page 305 IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Installation NOTE: Rotor/sensor wheel are sold as an assembly only. 1. Ensure that carbon brush tang has a 1/4 in. (6 mm) gap between rotor and tang. 72731 1/4 in. (6 mm) 2. Put 2 drops of Loctite 27131 into the rotor so it lands on the locating key. 3.
Page 306: Sensor
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Sensor Testing 1. Disconnect the two sensor wires from the wiring harness. 2. Using an Ohmmeter, check for an ohm reading between the two sensor wires. If reading is less than 100 ohms, replace sensor. Removal 1.
Page 307: Installation
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Installation 1. Install sensor into housing and install two retaining screws. 2. Install sensor wheel, rotor and distributor cap. 3. Connect WHT/RED and WHT/GRN sensor wires (ring terminals on engine harness wires, or bullet connectors from Ignition Module wires). Tighten hex nuts securely (if equipped).
Page 308: Distributor Installation
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 6. Using these holes as guides, drill through other side of gear with a 3/16 in. carbide tipped drill. IMPORTANT: If a new gear has only a dimple, you will have to drill through one side of the gear before you slide gear onto shaft.
Page 309 IGNITION SYSTEM SERVICE MANUAL NUMBER 24 ENGINE ROTATED 1. Locate No. 1 piston in firing position by following instructions a. or b. below: a. Remove No. 1 spark plug and, with finger on plug hole, crank engine until compres- sion is felt in No. 1 cylinder. b.
Page 310: Replacing Distributor Gear
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Replacing Distributor Gear Removal 1. Remove rotor and sensor wheel. 2. Remove roll pin, washer and driven gear from distributor shaft. 3. Check for side play between shaft and distributor housing bushings. Maximum side play is 0.002 in.
Page 311: Gm Est Distributor
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 GM EST Distributor NOTICE Refer to “Service Precautions” in the front of this section BEFORE proceeding. Removal 1. Disconnect electrical connectors at distributor module. 2. Remove distributor cap and set it aside. 3. Scribe a line on distributor housing marking position of rotor. Also, mark position of distributor housing on intake manifold.
Page 312: Cleaning And Inspection
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 NOTE: Whenever disassembling distributor, the retainer must be replaced. DO NOT attempt to use old retainer. 1. Remove rotor from shaft by lifting or prying straight up. 2. Remove roll pin. 72917 Gear Roll Pin 3.
Page 313: Testing Pickup Coil
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Testing Pickup Coil 1. Connect an ohmmeter to either pickup coil lead and the housing. If the reading is NOT infinite, replace the pickup coil. 2. Connect an ohmmeter to both pickup coil leads. Flex the leads by hand at the coil and the connector to locate any intermittent opens.
Page 314: Installation
IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Installation 1. Align rotor, housing and intake manifold using scribe marks. 2. Slowly lower distributor (with gasket) through intake manifold and into position. If distrib- utor shaft won’t drop into position, pull it out and insert a screwdriver into the hole to turn the oil pump drive shaft.
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Page 316: Section 4C - Charging System
CHARGING SYSTEM SERVICE MANUAL NUMBER 24 ELECTRICAL SYSTEM Section 4C - Charging System Table of Contents General Precautions ....4C-2 Testing ......4C-7 EFI Electrical System Precautions .
Page 317: Efi Electrical System Precautions
• DO NOT attempt diagnostics without proper, approved Service Tools. Replacement Parts Warning WARNING Electrical, ignition and fuel system components on your MerCruiser are designed and manufactured to comply with U.S. Coast Guard Rules and Regulations to mini- mize risks of fire and explosion.
Page 318: Multiple Efi Engine Battery Precautions
CHARGING SYSTEM SERVICE MANUAL NUMBER 24 Multiple EFI Engine Battery Precautions Situation Alternators: They are designed to charge the battery that supplies electrical power to the engine that the alternator is mounted on. When batteries for two different engines are con- nected, one alternator will supply all the charging current for both batteries.
Page 319 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 Identification 72078 Mando 55 Amp and 65 Amp Alternator Excitation Wire - PURPLE Sensing Wire - RED/PURPLE Part Number and Amperage Rating (Hidden In This View) 72078 Delco 65 Amp Alternator Part Number Specifications Mando Description Specification...
Page 320 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 DelcoRemy Description Specification Rating 12 (V) x 65 (A) Output (1300 / 2500 / 6500 Grpm) 8 / 47 / 65 (A) @ 20’ Regulator Setting Voltage 14.4 - 15 Volts @ 25’ Tools Description Part Number Bearing Removal and Installation Kit...
Page 321 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 Description This package uses an integral regulator charging system. The integrated circuit regulator is a solid state unit that is mounted inside the alternator to the slip ring end frames. All regula- tor components are enclosed in a solid mold to protect them from the heat and corrosive elements.
Page 322 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 Testing Charging System 1. Check belt condition and tension. 2. Check battery condition. – – 76498 3. With a fully charged battery, connect voltmeter leads directly to the battery posts. 4. Start engine and run at 1300-1500 rpm. Read voltmeter. Most systems will read 13.8-14.8 volts.
Page 323 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 Charging System Resistance 1. Ground the ignition coil high tension wire so engine does not start. 2. Crank engine over for 15 seconds to discharge the battery slightly. 3. Reconnect coil high tension wire and turn off all accessories. 4.
Page 324 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 6. Connect the voltmeter negative (–) lead to the alternator ground terminal. Connect volt- meter positive (+) lead to the battery negative (–) post. – – 76498 76533 Typical Output Terminal Ground Terminal Voltmeter Battery 7.
Page 325 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 Circuitry Perform the following tests, using a 0-20 volt DC voltmeter, to check that all of the circuits between the alternator and the other components within the alternator system are in good condition. OUTPUT CIRCUIT 1.
Page 326 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 SENSING CIRCUIT 1. Unplug RED/PURPLE lead from voltage regulator. 2. Connect positive (+) voltmeter lead to red/purple lead and negative (–) voltmeter lead to ground terminal. 3. Voltmeter should indicate battery voltage. If battery voltage is not present, check sens- ing circuit (red/purple lead) for loose or dirty connection or damaged wiring.
Page 327 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 c. If reading is high or infinite (no meter movement), high resistance or an open exists in the field circuit. Check for poor connections between field winding leads and slip ring terminals. If cause for open or high resistance cannot be found, connect ohm- meter directly to slip ring terminals.
Page 328 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 b. Continuity should be present in all three cases (meter should move). If it does not, one or more of the windings are open and stator must be replaced. 72833 Testing Stator Test 1 Test 2 3.
Page 329 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 5. Replace assembly if any of the rectifiers is shorted or open. 72147 Heat Sink Rectifier Terminal Test These Two Rectifiers In The Same Manner POSITIVE (+) RECTIFIER AND DIODES CAUTION DO NOT use a test instrument with more than a 12 volt source (in the following test), as rectifier may be damaged.
Page 330 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 11. Connect one lead of an ohmmeter (set on R x1) to the common side of the diode and the other lead to the other side, of one of the three diodes. 72148 Common Side Of Diode Circuit Board Repeat Test For Two Diodes 12.
Page 331 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 Exploded View 72276 Screws (3) 16 - Flat Washer Nut (9) 17 - Screw Flat Washer (4) 18 - Stator Sensing Wire (RED / PUR) 19 - Rotor And Slip Ring Excitation Wire (PUR) 20 - Retaining Plate Cover...
Page 332: Removal
CHARGING SYSTEM SERVICE MANUAL NUMBER 24 Alternator Repair Removal 1. Disconnect negative (–) battery cable from battery. 2. Disconnect wiring harness from alternator. 3. Loosen serpentine belt with the adjustment pulley. 4. Turn the adjustment stud and loosen belt. Remove belt. 5.
Page 333 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 2. Disconnect regulator leads from terminals on rear end frame. Remove four nuts, Phillips head screw and two regulator leads. Then pull regulator cover away from rear end frame. 72963 Regulator Leads Nuts (4) Phillips Head Screw Regulator Cover 3.
Page 334 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 7. Separate rear end frame and stator assembly from front end frame and rotor assembly using two thin blade screwdrivers (positioned 180 degrees apart from one another) at the locations shown. Use the two slots shown to initially separate units. 72824 DO NOT Insert Screwdriver Blades More Than 1/16 In.
Page 335 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 11. Unsolder the three stator leads from the rectifier heat sink. Place a needle nose pliers on diode terminal between solder joint and diode body to help prevent heat damage to diodes. Unsolder joints as quickly as possible and allow diode terminal to cool before removing pliers.
Page 336 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 13. Remove the three phillips head screws and lockwashers which secure the front bearing retaining plate. 72829 Phillips Head Screws and Lockwashers Front Bearing Retaining Plate 14. Remove front bearing from front end frame using an arbor press and a suitable size mandrel.
Page 337: Cleaning And Inspection
CHARGING SYSTEM SERVICE MANUAL NUMBER 24 Cleaning and Inspection 1. Clean all parts with a clean, soft cloth. DO NOT use solvent, or electrical components may be damaged. 2. Inspect the following parts for wear and damage: a. Brush/regulator assembly - inspect for cracked casing, damaged brush leads, poor brush lead solder connections, weak or broken brush springs or worn brushes.
Page 338 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 2. Install front bearing retaining plate using three Phillips head screws and lockwashers. 72829 Phillips Head Screws And Lockwashers Front Bearing Retaining Plate 3. Slide front end frame over rotor. 4. Assemble stator to rectifier by soldering the three leads to the three rectifier terminals. 72826 Stator Lead Connections NOTE: Be sure to connect leads to their original positions.
Page 339 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 7. Position rear end frame and stator assembly over front end frame and rotor assembly and align scribe marks on each (scribed during disassembly). Hand-press end frames together, then install four screws. Tighten screws securely. 72561 Rear End Frame Stator...
Page 340 CHARGING SYSTEM SERVICE MANUAL NUMBER 24 10. Install tie bar to rectifier stud and stud on brush/rectifier assembly. Tighten nuts securely. 72823 Studs Tie Bar 11. Install cover with one phillips head screw and two nuts. Install two leads with nuts. 72963 Phillips Head Screw Nuts (4)
Page 341: Installation
CHARGING SYSTEM SERVICE MANUAL NUMBER 24 Installation 1. Position alternator in mounting bracket and install mounting bolts. Torque to 35 lb-ft (48 Nm). 75713 76471 Typical Models V-Drive Models Bracket Bolts 2. Position alternator drive belt on pulleys and adjust tension as explained under “Drive Belt Tension Adjustment,”...
Page 342: Pulley Removal
CHARGING SYSTEM SERVICE MANUAL NUMBER 24 Pulley Removal 1. Remove serpentine belt. 2. Clamp pulley in a vise (using an old belt or protective jaws to protect pulley) to remove nut. 72828 Old Belt to Protect Pulley 3. Slide components off of alternator shaft. 4.
Page 343: Battery Isolator Diagram
CHARGING SYSTEM SERVICE MANUAL NUMBER 24 Battery Isolator Diagram 72934 Circuit Breaker Harness Connector Alternator Starter Cranking Battery Ground Stud Auxiliary Battery Isolator Disconnect Orange Wire From Alternator Battery Terminal. Splice Sufficient Gauge Wire To The Orange Wire And Connect As Shown. 8 Gauge Minimum Index Page 4C-28...
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Page 346 INSTRUMENTATION SERVICE MANUAL NUMBER 24 ELECTRICAL SYSTEM Section 4D - Instrumentation Table of Contents Tools ......4D-2 Senders .
Page 347 INSTRUMENTATION SERVICE MANUAL NUMBER 24 Tools Description Part Number Voltmeter Ohmmeter Obtain Locally Service Tachometer Continuity Meter Lubricants / Sealants / Adhesives Description Part Number Quicksilver Liquid Neoprene 92-25711--3 Loctite Pipe Sealant with Teflon Obtain Locally Identification 72965 76372 76373 Battery 12v Terminal Ground Terminal Sender Terminal...
Page 348 INSTRUMENTATION SERVICE MANUAL NUMBER 24 Description Lighting Options Some gauges may be wired so that the illumination lighting is provided from the ignition switch or a separate instrumentation lighting switch. By removing contact strip “I” from be- tween + terminal and the screw as shown following, and supplying a separate +12 V power supply to the screw connection, illumination lights can be operated independent of ignition switch.
Page 349 INSTRUMENTATION SERVICE MANUAL NUMBER 24 Gauges Circuits Typical gauges are shown. One terminal is the positive (+), the second terminal is the ground (–) and the third terminal is the light. Some gauges will have a terminal for the sender (S). The information below is how most gauges are marked.
Page 350 INSTRUMENTATION SERVICE MANUAL NUMBER 24 3. Turn ignition switch to RUN. Indicator needle on gauge should be positioned as shown. 72747 Typical 4. Turn ignition switch to OFF. 5. Connect jumper wire from ground terminal to sender terminal. 72748 Typical 6.
Page 351 INSTRUMENTATION SERVICE MANUAL NUMBER 24 Battery Gauge TESTING 1. Use a fully charged 12v battery. Check voltage with voltmeter. 2. Connect a jumper wire from the positive (+) battery post to the positive (+) gauge terminal. 3. Connect a jumper wire from the negative (–) battery post to the (–) gauge terminal. 72750 Typical 4.
Page 352 INSTRUMENTATION SERVICE MANUAL NUMBER 24 Cruiselog Meter TESTING 1. Connect jumper wire from positive (+) battery terminal to positive (+) gauge terminal. 2. Connect jumper wire from negative (–) battery terminal to negative (–) gauge terminal. 72752 3. Observe gauge run indicator. If indicator is not turning, replace gauge. 72753 Indicator Vacuum Gauge...
Page 353 INSTRUMENTATION SERVICE MANUAL NUMBER 24 Speedometer TESTING IMPORTANT: When testing speedometer gauge for accuracy, the air supply used for the test must be regulated to the specified air pressure. Do not apply excessive air pressure to speedometer gauge. 1. Apply air pressure directly to speedometer gauge (specified in chart) and note gauge reading.
Page 354 INSTRUMENTATION SERVICE MANUAL NUMBER 24 Senders Oil Pressure TESTING IMPORTANT: Use following test procedure for checking accuracy of oil pressure sender only. If oil pressure gauge indicates zero oil pressure, refer to SECTION 1C - “Troubleshooting.” 1. Remove wire from sender terminal. 2.
Page 355: Water Temperature
INSTRUMENTATION SERVICE MANUAL NUMBER 24 Water Temperature REMOVAL 1. Drain coolant from closed cooling system into a suitable container. Refer to SECTION 2. Remove TAN wire from temperature sender. NOTE: Hoses are shown removed for clarity. 3. Remove temperature sender. Water Temperature Sender Thermostat Housing TESTING...
Page 356 INSTRUMENTATION SERVICE MANUAL NUMBER 24 NOTE: While water cools you may recheck ohmmeter readings. 72769 Suitable Container Thermometer Heat Source Water Temperature Ohmmeter Leads Water Temperature Ohms Reading 140° F (60° C) 121-147 194° F (90° C) 47-55 212° F (100° C) 36-41 6.
Page 357 INSTRUMENTATION SERVICE MANUAL NUMBER 24 Switches Ignition Key Switch TESTING CAUTION Disconnect battery cables from battery before testing ignition key switch with wires still connected to switch. 1. Disconnect battery cables, if testing ignition key switch with wires connected to switch. 2.
Page 358 INSTRUMENTATION SERVICE MANUAL NUMBER 24 Lanyard Stop Switches NOTICE For repair procedures on fuel injected engines, refer to SECTION 5. TESTING 1. Disconnect switch leads. 2. Connect an ohmmeter to leads. 3. There should be continuity with switch lanyard connected and no continuity with switch lanyard disconnected.
Page 359: Audio Warning System
INSTRUMENTATION SERVICE MANUAL NUMBER 24 Start/Stop Switch TESTING WARNING Disconnect battery leads at battery before testing. 1. Disconnect battery leads. 2. Check for continuity between the terminals on the start switch with a continuity meter. 72763 3. No continuity should exist. 4.
Page 360: Oil Pressure Switch
INSTRUMENTATION SERVICE MANUAL NUMBER 24 Oil Pressure Switch TESTING 1. Remove wire from sender terminal. 2. Connect continuity meter between sender terminal and sender hex. (Sender shown removed for clarity.) 72764 3. With engine not running, meter should indicate full continuity. 4.
Page 361 INSTRUMENTATION SERVICE MANUAL NUMBER 24 TESTING 1. Connect one lead of an ohmmeter to one terminal of transmission switch. Connect the other lead of ohmmeter to other terminal. 72771 Ohmmeter Leads Transmission Fluid Temperature Switch 2. Switches should read no continuity. If continuity exists, replace the switch. WARNING The following test involves the use of intense heat.
Page 362 INSTRUMENTATION SERVICE MANUAL NUMBER 24 4. Heat sand and observe thermometer and ohmmeter. 72772 Suitable Container Thermometer Heat Source Switch or sensor Ohmmeter Leads 5. As temperature rises, switch will close and ohmmeter will indicate continuity. Refer to chart below for specifications. Coolant Temperature Switch Opens Closes...
Page 363 INSTRUMENTATION SERVICE MANUAL NUMBER 24 INSTALLATION 1. Apply Loctite Pipe Sealant with Teflon to threads of transmission fluid temperature switch. 2. Install switch with sealing washer in transmission and tighten securely. 3. Reconnect harness wires and coat with Liquid Neoprene. 72845 Transmission Fluid Temperature Switch Typical Location Switch With Sealing Washer...
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Page 366 WIRING DIAGRAMS SERVICE MANUAL NUMBER 24 ELECTRICAL SYSTEMS Section 4E - Wiring Diagrams Table of Contents Starting and Charging Harness ..4E-2 Fuel and Ignition System Harness ..4E-14 MCM 5.0L Engines .
Page 367 MAINTENANCE SERVICE MANUAL NUMBER Starting and Charging Harness MCM 5.0L Engines BLK = Black BLU = Blue BRN = Brown GRY = Gray GRN = Green ORN = Orange PNK = Pink PUR = Purple RED = Red TAN = Tan WHT = White YEL = Yellow LIT = Light...
Page 368 WIRING DIAGRAMS SERVICE MANUAL NUMBER 24 A - Ignition Components Distributor Timing Lead Ignition Coil Shift Interrupt Switch (not used on Bravo) B- Starting, Charging and Choke Components Alternator Electric Choke Ground Stud Starter Motor Oil Pressure Switch Fuel Pump Starter Slave Solenoid C - Audio Warning Components Oil Pressure Switch...
Page 369 MAINTENANCE SERVICE MANUAL NUMBER MCM 5.7L Engines BLK = Black BLU = Blue BRN = Brown GRY = Gray GRN = Green ORN = Orange PNK = Pink PUR = Purple RED = Red TAN = Tan WHT = White YEL = Yellow LIT = Light DRK = Dark...
Page 370 WIRING DIAGRAMS SERVICE MANUAL NUMBER 24 A - Ignition Components Distributor Timing Lead Knock Sensor Ignition Coil Shift Interrupt Switch (not used on Bravo) B- Starting, Charging and Choke Components Alternator Electric Choke Ground Stud Starter Motor Oil Pressure Switch Fuel Pump Circuit Breaker Starter Slave Solenoid...
Page 371 MAINTENANCE SERVICE MANUAL NUMBER MEFI 1 and MEFI 2 MCM 5.0L EFI, 5.7L EFI and 350 Mag MPI Engines BLK = BLACK BLU = BLUE BRN = BROWN GRY = GRAY GRN = GREEN ORN = ORANGE PNK = PINK PUR = PURPLE RED = RED TAN = TAN...
Page 372 WIRING DIAGRAMS SERVICE MANUAL NUMBER 24 A - Audio Warning Components Oil Pressure Switch Drive Unit Oil Level B - Instrumentation Components Oil Pressure Sender Water Temperature Sender Trim Sender C - Charging and Starting Components Alternator Ground Stud Starter Circuit Breaker Starter Slave Solenoid Positive Power Wire To EFI System...
Page 373 MAINTENANCE SERVICE MANUAL NUMBER MEFI 3 MCM 5.0L EFI, 5.7L EFI and 350 Mag MPI Engines 90 Amp Fuse 76061 Index Page 4E-8 90-861327--1 OCTOBER 1999...
Page 374 WIRING DIAGRAMS SERVICE MANUAL NUMBER 24 A - Audio Warning Components Oil Pressure Switch B - Instrumentation Components Oil Pressure Sender Trim Sender C - Charging and Starting Components Alternator Ground Stud Starter Circuit Breaker Starter Slave Solenoid Jumper Wire Connection Battery Positive Power Wire To EFI System Harness Harness Connector To EFI System Harness...
Page 375 MAINTENANCE SERVICE MANUAL NUMBER MIE 5.7L Inboard BLK = Black BLU = Blue BRN = Brown GRY = Gray GRN = Green ORN = Orange PNK = Pink PUR = Purple RED = Red TAN = Tan WHT = White YEL = Yellow LIT = Light DRK = Dark...
Page 376 WIRING DIAGRAMS SERVICE MANUAL NUMBER 24 A - Ignition Components Distributor Timing Lead Knock Sensor Ignition Coil B - Starting, Charging and Choke Components Alternator Electric Choke Ground Plug Starter Motor Oil Pressure Switch Fuel Pump Circuit Breaker Neutral Safety Switch Starter Slave Solenoid C - Audio Warning Components Oil Pressure Switch...
Page 377 MAINTENANCE SERVICE MANUAL NUMBER MIE 350 Mag MPI and Black Scorpion Engines - Starting and Charging System Harness NOTE: Taped back BROWN-WHITE wire may be used for an Accessory. LOAD MUST NOT EXCEED 5 AMPS. BLK = BLACK BLU = BLUE BRN = BROWN GRY = GRAY GRN = GREEN...
Page 378 WIRING DIAGRAMS SERVICE MANUAL NUMBER 24 A - Audio Warning Components Transmission Temperature Switch B - Instrumentation Components Oil Pressure Sender Wire Not Used C - Charging and Starting Components Alternator Ground Stud Starter 90 Amp Fuse (DO NOT REMOVE) Circuit Breaker Starter Slave Solenoid Neutral Safety Switch...
Page 379 MAINTENANCE SERVICE MANUAL NUMBER Fuel and Ignition System Harness MEFI 1 MCM 5.0L EFI and 5.7L EFI Alpha Engines Fuel Pump 12 - Electronic Control Module (ECM) Throttle Body 13 - Fuel Pump Relay Distributor 14 - Ignition/System Relay Coil 15 - Fuse (15 Amp) Fuel Pump Electronic Spark Control (KS) Module...
Page 380 WIRING DIAGRAMS SERVICE MANUAL NUMBER 24 MEFI 3 5.0L EFI and 5.7L EFI Engines NOTE: All BLACK wires with a ground symbol are interconnected within the EFI system har- ness. Fuel Pump Electronic Control Module (ECM) Throttle Body Water Temperature Sender Distributor Fuel Pump Relay Coil...
Page 381 MAINTENANCE SERVICE MANUAL NUMBER MEFI 1 and MEFI 2 MCM 350 Mag MPI Bravo Engines NOTE: All BLACK wires with a ground symbol are interconnected within the EFI system har- ness. NOTE: Component position and orientation shown is arranged for visual clarity and ease of circuit identification.
Page 382 WIRING DIAGRAMS SERVICE MANUAL NUMBER 24 MEFI 3 350 Magnum MPI and All Black Scorpion Engines NOTE: All BLACK wires with a ground symbol are interconnected within the EFI system har- ness. NOTE: Component position and orientation shown is arranged for visual clarity and ease of circuit identification.
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Page 384 FUEL DELIVERY SYSTEM FOR CARBURETED ENGINES SERVICE MANUAL NUMBER 24 FUEL SYSTEM Section 5A - Fuel Delivery System For Carbureted Engines Table of Contents Identification ......5A-2 Fuel Delivery System .
Page 385 Fuel Pump Replacement Parts Warning WARNING Electrical, ignition and fuel system components on your MerCruiser are designed and manufactured to comply with U.S. Coast Guard Rules and Regulations to mini- mize risks of fire and explosion. Use of replacement electrical, ignition or fuel system components, which do not comply with these rules and regulations, could result in a fire or explosion hazard and should be avoided.
Page 386 FUEL DELIVERY SYSTEM FOR CARBURETED ENGINES SERVICE MANUAL NUMBER 24 Tools Description Part Number Fuel Pressure Connector (Carburetor) 91-18078 Fuel Pressure Gauge Obtain Locally Lubricants / Sealants / Adhesives Description Part Number Quicksilver Perfect Seal 92-34227--1 #592 Loctite Pipe Sealant with Teflon Obtain Locally Precautions WARNING...
Page 387 FUEL DELIVERY SYSTEM FOR CARBURETED ENGINES SERVICE MANUAL NUMBER 24 Fuel Delivery System Recommendations WARNING Boating standards (NMMA, ABYC, etc.) and Coast Guard regulations must be adhered to when installing fuel delivery system GENERAL The fuel tank is an integrated component of the boat. Refer to the special information on service and maintenance that you have received from the tank manufacturer.
Page 388: Fuel System Components
FUEL DELIVERY SYSTEM FOR CARBURETED ENGINES SERVICE MANUAL NUMBER 24 5. Larger diameter (than previously specified) lines and fittings must be used on installa- tions requiring long lines or numerous fittings. 6. Fuel line(s) should be installed free of stress and firmly secured to prevent vibration and/ or chafing.
Page 389 FUEL DELIVERY SYSTEM FOR CARBURETED ENGINES SERVICE MANUAL NUMBER 24 Replacement NOTICE Refer to “Precautions” in this section, BEFORE proceeding. 1. Disconnect battery cables from battery. 2. Remove fuel filter from base. A filter wrench may be needed to loosen element. 3.
Page 390 FUEL DELIVERY SYSTEM FOR CARBURETED ENGINES SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index 90-861327--1 OCTOBER 1999 Page 5A-7...
Page 391 FUEL DELIVERY SYSTEM FOR CARBURETED ENGINES SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 5A-8 90-861327--1 OCTOBER 1999...
Page 392: Section 5B - Mercarb
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 FUEL SYSTEM  Section 5B - Mercarb 2 Barrel Carburetor Table of Contents Identification ......5B-2 Fuel Inlet Filter .
Page 393 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Identification 33049565 2301 72680 2 Barrel MerCarb Carburetor Part Number Location Part Number Date Code Date Code Explanation: Example 2301 First Figure is Year: 2 = 1992, 3 = 1993, etc. Second Figure is Month: 2 = February, 3 = March, etc.
Page 394: Replacement Parts Warning
SERVICE MANUAL NUMBER 24 Replacement Parts Warning WARNING Electrical, ignition and fuel system components on your Mercury MerCruiser are designed and manufactured to comply with U.S. Coast Guard Rules and Regula- tions to minimize risks of fire and explosion. Use of replacement electrical, ignition or fuel system components, that do not com- ply with these rules and regulations could result in a fire or explosion hazard and should be avoided.
Page 395: Fuel Delivery System
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Fuel Delivery System Recommendations WARNING Boating standards (NMMA, ABYC, etc.) and Coast Guard regulations must be ad- hered to when installing fuel delivery system. The Fuel Tank is an integrated component of the boat. Refer to the special information on service and maintenance, which you have received from the tank or boat manufacturer.
Page 396: Torque Specifications
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Torque Specifications Description lb-in. lb-ft Carburetor To Manifold Fuel Line to Carburetor Fuel Inlet Filter Nut Tools Description Part Number Tachometer 79-17391A1 Universal Carburetor Gauge 91-36392 Float Gram Scale Obtain Locally Specifications Engine Model 5.0L 5.7L...
Page 397: High Altitude Re-Jetting
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 High Altitude Re-Jetting Engine flooding problems, at idle rpm, are generally related to the altitude (above sea level) at which they are operated. If engine is running too rich at higher elevation, order a smaller jet from the chart.
Page 398: Important Service Information
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Important Service Information 8 Point Carburetor Check List To ensure that the carburetor is the cause of the problem, make the following checks BEFORE ordering and installing a new carburetor. If questions 1, 2, 3, 5, 6 and 7 are YES and 8 is NO, the carburetor may not be the problem.
Page 399: Description
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Adjustable Accelerator Pump Lever This new 3 hole lever allows you to change the amount of fuel delivered to the engine by the accelerator pump. The hole closest to the lever’s shaft will give the same amount of fuel as the single hole lever did.
Page 400: Flame Arrestor With Carburetor Cover 5B-9
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Maintenance Flame Arrestor with Carburetor Cover NOTICE Refer to “Precautions” in this section, BEFORE proceeding. REMOVAL 1. Remove nut. 2. Remove sealing washer. 3. Remove carburetor cover. 4. Remove crankcase ventilation hose from flame arrestor and starboard rocker arm cover.
Page 401 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 INSTALLATION 1. Install flame arrestor. 2. Install crankcase ventilation hose to flame arrestor and starboard rocker arm cover. 3. Install positive crankcase vent (PCV) hose from port rocker arm PCV valve connection to carburetor tube.
Page 402 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Fuel Inlet Filter NOTICE Refer to “Precautions” in this section, BEFORE proceeding. REMOVAL 1. Remove fuel line from fuel inlet filter nut. 2. Remove fuel inlet filter nut and small gasket. 3. Remove large gasket. 4.
Page 403: Choke Inspection
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Choke Inspection The choke does not require any periodic maintenance. However, if a choke malfunction is suspected, the following should be done: 1. With engine turned OFF, remove flame arrestor. 2. Open and close choke several times to check for binding, loose or disconnected link- ages or other signs of damage.
Page 404 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 2. With throttle valves completely closed, measure from flame arrestor mounting surface to top of pump rod. 72682 See Specifications 3. Carefully bend pump rod (where shown) to obtain specified dimension. 72683 Pump Rod Bend Here Index...
Page 405: Choke Setting
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Choke Setting Normal choke setting: mark on cover is set 2 index marks clockwise from larger, center index mark. If choke adjustment is necessary: 1. Loosen choke cover retaining screws. 2. Adjust as shown. 3.
Page 406 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 4. Bend tang on throttle lever, if necessary, to obtain specified dimension. 72685 Tang Throttle Lever Initial Idle Speed and Mixture IMPORTANT: The following adjustments will provide a sufficient idle speed and mix- ture for starting engine.
Page 407: Final Idle Speed And Mixture
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Final Idle Speed and Mixture The ignition module must be locked into the timing mode to adjust idle speed and mixture. Refer to SECTION 4B - “Timing - Thunderbolt V Models.” EMISSIONS CARBURETOR Sealed Carburetor Mixture Screw The carburetor on this engine has a seal on the carburetor mixture screw.
Page 408: Repair
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Repair NOTICE Refer to “Precautions” in this section, BEFORE proceeding. Removal IMPORTANT: Carburetor problems are, in many cases, caused by the presence of dirt, water or other foreign matter in carburetor. To aid in diagnosis, carefully remove carburetor from engine without draining fuel from bowl.
Page 409 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Exploded View 75842 Index Page 5B-18 90-861327--1 OCTOBER 1999...
Page 410: Exploded View Parts List
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Exploded View Parts List Rod - Accelerator Pump 29 - Washer Accelerator Pump Shaft and Lever 30 - Assembly 31 - Clip-Pump Rod Washer (Outer) 32 - Washer-Locking Washer (Inner) 33 - Screw 34 - Throttle Lever...
Page 411: Disassembly
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Disassembly IMPORTANT: Before performing any service on carburetor, it is essential that carbu- retor be placed in a holding fixture to prevent possible damage to throttle valves. The following is a step-by-step procedure for completely overhauling the carburetor removed from engine.
Page 412 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 AIR HORN 1. Remove fuel inlet filter nut, washers, spring, and filter, as outlined previously. 2. Remove accelerator pump rod retaining clip. 3. Pivot rod (as required) until retaining ear on rod and slot in pump shaft and lever assem- bly align, allowing rod to be pulled out.
Page 413 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 5. Remove choke rod by pivoting rod (as required) until retaining ear on rod and slot in choke lever align, allowing rod to be pulled out. 72286 Choke Rod Choke Lever Slot 6.
Page 414 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 9. Remove float hinge pin and lift float assembly from air horn. 72288 Float Hinge Pin Float Assembly 10. Check float weight as shown. 72122 Grams Scale Float 11. Remove air horn gasket and baffle. 72399 Baffle Air Horn Gasket...
Page 415 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 12. Remove needle assembly. 72287 Needle Assembly Needle Seat 13. Remove needle seat. 72289 Needle Seat Gasket Screwdriver 72290 Needle and Seat Assemblies Spring Loaded Type Needle (Kit 3302-9029) Solid Type Needle (Kit 3302-9407) Index Page 5B-24 90-861327--1 OCTOBER 1999...
Page 416 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 14. Loosen accelerator pump screw. 15. Slide pump shaft and lever assembly (and washer) out of air horn. 16. Remove accelerator pump assembly. 72398 Set Screw Lever Assembly Pump Assembly 17. Remove retainer clip and washer from pump shaft and lever assembly, then remove accelerator pump assembly.
Page 417 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 2. Remove power valve assembly and gasket. 72404 Power Valve Assembly Gasket (Not Shown) 3. Remove main metering jets. 72291 Main Metering Jets Gaskets (Not Shown) IMPORTANT: Use care when removing venturi cluster to prevent damaging brass tubes which protrude from bottom of cluster.
Page 418 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 5. Using a needle-nose pliers, remove accelerator pump check ball spring retainer. Turn float bowl over to remove spring and check ball. 72407 Spring Retainer Spring and Check Ball (Not Shown) IMPORTANT: Use extreme care when handling carburetor body, so as not to damage throttle valves.
Page 419: Cleaning And Inspection
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Cleaning and Inspection IMPORTANT: DO NOT use a wire or drill to clean jet passages or tubes in carburetor, as this may enlarge orifices and seriously affect carburetor calibration. CAUTION To avoid damage to carburetor DO NOT leave carburetor in immersion type carbure- tor cleaner for more than two hours.
Page 420 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 d. Accelerator Pump Plunger and Return Spring: Inspect pump plunger cup, pump plunger spring (on pump assembly) and return spring. e. Power Piston Spring: Check power piston spring for weakness or distortion. Idle Mixture Needle: Inspect idle mixture needle.
Page 421: Reassembly
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Reassembly CARBURETOR BODY IMPORTANT: DO NOT force idle mixture needle against seat as damage to needle and/or seat will result. 1. Screw idle mixture needle and spring into throttle body until they lightly seat, then back out needle 1-1/2 turns as a preliminary idle mixture setting.
Page 422 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 FLOAT BOWL IMPORTANT: Place float bowl and throttle assemblies in holding fixture to prevent throttle valves from being damaged. 1. Install check ball, spring, and retainer in passage. Push retainer firmly into slots. 72408 Check Ball Spring...
Page 423 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 IMPORTANT: Do not damage the fiber washer. A damaged washer will cause improper fueling. 72405 Center Screw Outer Screws Fiber Washer Lock Washer and Flat Washer 5. Install main metering jets with gaskets. Tighten securely. 72291 Main Metering Jets Gaskets (Not Shown)
Page 424 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 7. Place accelerator pump spring in pump well. 72402 Accelerator Pump Spring AIR HORN IMPORTANT: Accelerator pump assembly MUST BE installed correctly. If pump assembly is installed incorrectly, top of pump assembly will contact air horn casting. 1.
Page 425 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 5. Install needle seat and gasket. Tighten securely. 72289 Needle Seat Gasket Screwdriver IMPORTANT: Float needle and needle seat are factory matched and tested and should be replaced as a set only. 6.
Page 426 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 8. Install float assembly and hinge pin. Pivot float assembly up and down on hinge pin to ensure it moves freely. 72297 Float Assembly Float Hinge Pin FLOAT LEVEL 1. Turn air horn upside down. Pivot float assembly up and down on hinge pin to ensure it moves freely.
Page 427 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 3. Bend float arm up or down at point shown to obtain specified dimension. 72688 Bend Float Arm at This Point 4. Visually check float alignment after adjustment. FLOAT DROP 1. Hold air horn right side up to allow float to hang free. 2.
Page 428 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 5. Place air horn on float bowl, making sure accelerator pump is correctly positioned in fuel well. Lower air horn straight down to install. 72400 Air Horn Assembly Float Bowl Assembly 6. Install seven short and one long air horn attaching screws. Tighten screws evenly and securely.
Page 429 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 8. Place idle cam on choke rod. 72392 Idle Cam Choke Rod 9. Secure idle cam (with choke rod installed on cam) on float bowl assembly, using screw. Ensure that cam is free to move without binding. 72282 Screw Idle Cam...
Page 430 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 11. Insert other end of accelerator pump rod into hole in throttle lever and secure with retainer clip. 72283 Accelerator Pump Rod Throttle Lever Retainer Clip CHOKE HOUSING 1. Install choke housing on air horn. Tighten screws securely. 2.
Page 431: Installation
MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 Installation 1. Thoroughly clean gasket surfaces and install new gaskets. 2. Place new carburetor base gasket on intake manifold. 3. Install carburetor and secure with nuts and washers. Torque to 132 lb-in. (15 Nm). 4.
Page 432 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index 90-861327--1 OCTOBER 1999 Page 5B-41...
Page 433 MERCARB 2 BARREL CARBURETOR SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 5B-42 90-861327--1 OCTOBER 1999...
Page 434: Water Separating Fuel Filter
FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 FUEL SYSTEM Section 5C - Fuel Delivery System For Electronic Fuel Injection Table of Contents Specifications ..... . . 5C-2 Water Separating Fuel Filter .
Page 435 NOTE: Refer To “Fuel Supply Connections” Warning following this chart. Replacement Parts Warning WARNING Electrical, ignition and fuel system components on your MerCruiser are designed and manufactured to comply with U.S. Coast Guard Rules and Regulations to mini- mize risks of fire and explosion.
Page 436 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 Precautions WARNING Always disconnect battery cables from battery BEFORE working on fuel system to prevent fire or explosion. WARNING Be careful when changing fuel system components; gasoline is extremely flam- mable and highly explosive under certain conditions.
Page 437 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 Fuel Delivery System Recommendations WARNING Boating standards (NMMA, ABYC, etc.) and Coast Guard regulations must be ad- hered to when installing fuel delivery system. The Fuel Tank is an integrated component of the boat. Refer to the special information on service and maintenance, which you have received from the tank or boat manufacturer.
Page 438 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 Cool Fuel System Exploded View 75708 Exploded View Component List Bracket 14 - Fuel Cooler Cover Base 15 - Fuel Pump Wiring Harness Screw and Washer (2) 16 - Retainer Bracket Fuel Pressure Regulator 17 -...
Page 439 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 Fuel System Flow Diagrams Throttle Body Injection 74871 All Throttle Body Fuel Injection Is Similar Diaphragm Rupture Line To Flame Arrestor Fuel Pressure Regulator Fuel Cooler Electric Fuel Pump Water Separating Fuel Filter Fuel From Tank Direction Of Water Flow...
Page 440 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 Multi-Port Injection with MEFI 1 and MEFI 2 74871 350 Mag MPI Shown - Scorpion Is Similar Vacuum Line To Intake Manifold Base Fuel Pressure Regulator Fuel Cooler Electric Fuel Pump Water Separating Fuel Filter Fuel From Tank Direction Of Water Flow...
Page 441 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 Multi-Port Injection with MEFI 3 74871 350 Mag MPI Shown - Scorpion Is Similar Vacuum Line To Intake Manifold Base Fuel Pressure Regulator Fuel Cooler Electric Fuel Pump Water Separating Fuel Filter Fuel From Tank Direction Of Water Flow Fuel Line To Fuel Rail...
Page 442 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 Water Separating Fuel Filter NOTICE Refer to “Precautions,” in this section, BEFORE proceeding. MCM Model Shown Top Cover (Some Models) Insulator Plate Fuel Return Line from Regulator Brass Fitting Fuel Line to Fuel Pump Brass Fitting Fuel Filter Mounting Bracket...
Page 443: Cool Fuel System Repair
FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 Water Separating Fuel Filter Replacement NOTICE Refer to “Precautions,” in this section, BEFORE proceeding. 1. Disconnect battery cables from battery. 2. Remove fuel filter from base. A filter wrench may be needed. 3.
Page 444: Disassembly
FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 6. Disconnect fuel lines from water separating fuel filter adapter. 75533 Filter Adapter Fuel Lines 7. Disconnect the fuel line from the rail. 8. Remove the cover from the cool fuel system. 9.
Page 445: Reassembly
FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 Reassembly 1. Install the small filter (conical side DOWN) in the orifice of the new fuel cooler where the fuel pressure regulator mounts. 2. Install the regulator onto the cooler using the two screws with washers. Torque the screws to 53 lb-in.
Page 446 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 IMPORTANT: To prevent loss of the stepped screw used to secure the cooler-to-fuel rail fuel line, a retainer ring is provided. Do not remove the retainer or stepped screw. 75708 75708 Fuel Line O-Rings...
Page 447: Installation
FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 7. Apply a thin, even coating of Thermal Grease on all of the retainer bracket inside sur- faces where it contacts the cooler and the fuel pump when installed. Retainer Bracket Thermal Grease 8.
Page 448 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 b. Connect the fuel line to the fuel rail fitting at location shown. Tighten securely. 75716 Typical Fuel Line, Fuel Cooler-to-Fuel Rail Fuel Rail Fitting 5. On Black Scorpion: Install the cooler-to-fuel rail line as follows: a.
Page 449 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 CAUTION DO NOT operate engine without cooling water being supplied to seawater pickup pump, or pump impeller will be damaged and subsequent overheating damage may result. 10. Connect seawater hoses to Cool Fuel system. Tighten hose clamps securely. 11.
Page 450: Vacuum And Vent Hose Routing
FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 Vacuum And Vent Hose Routing 350 Mag MPI Models Throttle Body Adapter Cool Fuel Assembly Vacuum Hose - Throttle Body Adapter to Fuel Pressure Regulator on Cool Fuel Assembly Vent Hose - PCV Valve to Throttle Body Adapter Vent Hose - Valve Cover Fitting To Flame Arrestor PCV Valve...
Page 451: Scorpion Models
FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 Scorpion Models Throttle Body Adapter Cool Fuel Assembly Vacuum Hose - Forward Fitting On Intake Manifold To Fuel Pressure Regulator on Cool Fuel Assembly Vent Hose - PCV Valve to Throttle Body Adapter Vent Hose - Valve Cover to Flame Arrestor PCV Valve Vent Hose Fitting...
Page 452: Throttle Body Efi
FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 Throttle Body EFI Plenum Cool Fuel Assembly Diaphragm Rupture Hose - Fuel Pressure Regulator on Cool Fuel Assembly To Side of Flame Arrestor Vent Hose - PCV Valve to Throttle Body Adapter PCV Valve Vent Hose - Valve Cover Fitting To Flame Arrestor Valve Cover Fitting...
Page 453 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 5C-20 90-861327--1 OCTOBER 1999...
Page 454 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 FUEL SYSTEMS Section 5D - Fuel Injection Descriptions And System Operation Table of Contents Special Tools ..... . . 5D-2 Electronic Control Module (ECM) Service Precautions...
Page 455: Special Tools
Allows multi-meter connections with wiring J-35616 Adapter harness. Displays problem codes stored in the ECM. It also allows monitoring of various MerCruiser Scan circuits and components in the fuel injec- 94050m Tool Version 3.4 tion system. Allows for test firing injectors. (English) Tool can read MEFI 1, MEFI 2 and MEFI 3 ECM.
Page 456: Service Precautions
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 Special Tools (cont’d) NOTE: The High Impedance Multimeter that comes with the existing Outboard 2 Cycle EFI Tester, P/N 91-11001A2 meets the requirements listed above. NOTE: Quicksilver Digital Tachometer / Multi-Meter (DMT 2000) P/N 91-854009A1, meets the requirements listed above.
Page 457 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 • When a test light is specified, a “low-power” test light must be used. DO NOT use a high-wattage test light. While a particular brand of test light is not suggested, a sim- ple test, as shown below, on any test light will ensure it to be safe for system circuit testing.
Page 458: General Information
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 General Information Electrostatic Discharge Damage Electronic components are often designed to carry very low voltage and are susceptible to damage caused by electrostatic discharge. It is possible for less than 100 volts of static elec- tricity to cause damage to some electronic components.
Page 459: Wiring Connector Service
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 WIRE REPAIR 1. Locate damaged wire. 2. Remove insulation as required. 73048 3. Splice two wires together using splice clips and rosin core solder. 73048 4. Cover splice with heat shrink sleeve to insulate from other wires. 73048 Wiring Connector Service Most connectors in the engine compartment are protected against moisture and dirt that...
Page 460: Abbreviations
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 Abbreviations in. hg Inches Of Mercury Ignition BARO Barometric Pressure Injection Battery Positive Terminal, Bat- Kilopascal tery or System Voltage Battery Positive Knock Sensor System Circuit Kilovolts Manifold Absolute CONN Connector Pressure Cylinder...
Page 461: Intermittent Malfunction Indicator Lamp
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 ECM Self-Diagnostics The ECM performs a continual self-diagnosis on certain control functions. This diagnostic capability is complemented by the diagnostic procedures contained in this manual. The ECM’s language for communicating the source of a malfunction is a system of diagnostic codes.
Page 462: Reading Codes
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 Reading Codes The provision for communicating with the ECM is the Data Link Connector (DLC) connector. It is part of the EFI engine wiring harness, and is a 10-pin connector, which is electrically connected to the ECM.
Page 463: Scan Tools
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 Scan Tools The ECM can communicate a variety of information through the DLC connector. This data is transmitted at a high frequency which requires a scan tool for interpretation. With an understanding of the data which the tool displays, and knowledge of the circuits in- volved, the tool can be very useful in obtaining information which would be more difficult or impossible to obtain with other equipment.
Page 464: Non-Scan Diagnosis Of Driveability Concerns (With No Codes Set)
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 Non-Scan Diagnosis of Driveability Concerns (With No Codes Set) If a driveability concern still exists after following the diagnostic circuit check and reviewing “Troubleshooting,” an out-of-range sensor may be suspected. Because of the unique de- sign of the EFI system, fail-safes have been incorporated into the ECM to replace a sensed value with a default value in the case of a sensor malfunction or sensor wiring concern.
Page 465: Electronic Control Module (Ecm) And Sensors
SERVICE MANUAL NUMBER 24 Electronic Control Module (ECM) and Sensors General Description The MerCruiser Electronic Fuel Injection system is equipped with a computer that provides the operator with state-of-the-art control of fuel and spark delivery. Computers use voltage to send and receive information.
Page 466: Digital Signals
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 TWO-WIRE SENSOR (ECT) The following figure is the schematic of a 2-wire type sensor. This sensor is basically a vari- able resistor in series with a fixed-known resistor within the computer. By knowing the values of the input voltage and the voltage drop across the known resistor, the value of the variable resistor can be determined.
Page 467: Engine Control Module (Ecm)
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 The computer uses digital signals in a code that contains only ones and zeros. The high volt- age of the digital signal represents a one (1), and no voltage represents a zero (0). Each zero and each one is called a bit of information, or just a “bit.”...
Page 468: Speed Density System
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 ECM FUNCTION The ECM supplies 5 or 12 volts to power various sensors or switches. This is done through resistances in the ECM which are so high in value that a test light will not light when con- nected to the circuit.
Page 469: Ecm Input And Sensor Descriptions
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 ECM Input and Sensor Descriptions The following lists the sensors, switches, and other inputs used by the ECM to control its various systems. Although we will not cover them all in great detail, there will be a brief description of each.
Page 470 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 ENGINE COOLANT TEMPERATURE (ECT) SENSOR The Engine Coolant Temperature (ECT) Sensor is a thermistor (a resistor which changes value based on temperature) immersed in the engine coolant stream. Low coolant tempera- ture produces a high resistance, while high temperature causes low resistance.
Page 471 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 KNOCK SENSOR On MEFI 1 and MEFI 2, the knock sensor is mounted on the lower right side of the engine block. MEFI 3 models do not have a knock sensor module mounted on the engine; it is lo- cated internal to the ECM.
Page 472 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 KNOCK SENSOR CIRCUITRY (MEFI-3 MODELS ONLY) The MEFI-3 ECM is used with the knock sensor to control spark knock. The KS module cir- cuitry is within the MEFI-3 ECM. When spark knock is present, a small AC voltage signal is sent from the knock sensor to the ECM through pin connector J1-30.
Page 473: Spark Management
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 DISCRETE SWITCH INPUTS Several discrete switch inputs are utilized by the system to identify abnormal conditions that may affect engine operation. These switches are used in conjunction with the ECM to detect critical conditions to engine operation.
Page 474: Modes Of Operation
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 Modes Of Operation DISTRIBUTOR MODULE MODE (MEFI 1 AND MEFI 2 ONLY) The ignition system operates independent of the ECM. The distributor module module in the distributor maintains a base ignition timing and is able to advance timing to a total of 27 degrees.
Page 475: Base Ignition Timing
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 Base Ignition Timing In order to check or change base timing on a EFI system the ECM has to be entered into the service mode by using a scan tool or code tool. The ECM will stabilize timing to allow timing adjustment.
Page 476: Results Of Incorrect Operation
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 Base Ignition Timing (Continued) Ignition Coil Trigger Signal Battery Relay Module Advance Signal Converter Pick Up Coil Ground Manifold Coolant Temperature REF HI Bypass REF LO Grounded No Voltage Applied Not Grounded Voltage Applied Results of Incorrect Operation...
Page 477: Fuel Metering System
(EFI). Cool Fuel Systems This system was used on later MerCruiser MEFI-1, MEFI-2 and MEFI-3 ECM engines. This system has a fuel cooler and the electric fuel pump inside a box on the lower, port side of the engine.
Page 478 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 RUN MODE When the engine is started and rpm is above 300, the system operates in the run mode. The ECM will calculate the desired air/fuel ratio based on these ECM inputs: rpm, Manifold Abso- lute Pressure (MAP) sensor, and Engine Coolant Temperature (ECT) sensor .
Page 479 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 MOVING DESIRED RPM MODE IMPORTANT: An improperly adjusted throttle cable can cause the engine idle rpm to be higher than the normal 600 rpm even when the control lever returns to the idle rpm position.
Page 480 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 THROTTLE BODY UNIT EXPLODED VIEW 73766 Throttle Body Idle Air Control (IAC) Valve Throttle Position (TP) Sensor Fuel Meter Cover Fuel Damper Fuel Meter Body Fuel Injector (2) Index 90-861327 OCTOBER 1999 Page 5D-27...
Page 481 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 FUEL INJECTORS The injector assembly is a solenoid operated device, controlled by the ECM, that meters pressurized fuel to the intake manifold. The ECM energizes the injector solenoid, which opens a ball valve, allowing fuel to flow past the ball valve, and through a recessed flow di- rector plate.
Page 482 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 FUEL DAMPER The fuel damper acts as an equalization device to reduce the pressure spikes caused by the fuel injectors. 76499 Fuel Damper IDLE AIR CONTROL (IAC) VALVE The purpose of the IAC valve assembly is to control engine idle speed, while preventing stalls due to changes in engine load.
Page 483: 350 Mag Mpi And Black Scorpion - Multi-Port Injection Components
FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 By moving a conical valve known as a pintle, IN, toward the seat (to decrease air flow), or OUT, away from the seat (to increase air flow), a controlled amount of air moves around the throttle valve.
Page 484 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 FUEL RAIL / INTAKE MANIFOLD ASSEMBLY The fuel rail performs several functions. It positions the injectors in the intake manifold, dis- tributes fuel evenly to the injectors. 75829 350 Mag MPI Models Fuel Rail Fuel Injector Intake Manifold...
Page 485 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 FUEL INJECTORS The EFI injector assembly is a solenoid-operated device, controlled by the ECM, that meters pressurized fuel to a single engine cylinder. The ECM grounds the injector solenoid, which opens a pintle valve, allowing fuel to flow past the pintle valve.
Page 486 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 FUEL PRESSURE REGULATOR ASSEMBLY MEFI 1 and MEFI 2 Only: The pressure regulator is a diaphragm-operated relief valve with fuel pump pressure on one side, and regulator spring pressure and intake manifold vacuum on the other.
Page 487 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 IDLE AIR CONTROL (IAC) VALVE The purpose of the IAC valve assembly is to control engine idle speed, while preventing stalls due to changes in engine load. The IAC valve, mounted in the throttle body, controls bypass air around the throttle valves.
Page 488 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index 90-861327 OCTOBER 1999 Page 5D-35...
Page 489 FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 5D-36 90-861327 OCTOBER 1999...
Page 490: Section 5E - Fuel Injection Disassembly And Reassembly
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 FUEL SYSTEM Section 5E - Fuel Injection Disassembly And Reassembly Table of Contents Service Precautions ....5E-2 MAP Sensor .
Page 491: Service Precautions
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Service Precautions WARNING Always disconnect battery cables from battery BEFORE working on fuel system to prevent fire or explosion. WARNING Be careful when cleaning flame arrestor and crankcase ventilation hose; gasoline is extremely flammable and highly explosive under certain conditions.
Page 492: Torque Specifications
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Torque Specifications Fastener Location lb-in. lb-ft Throttle Body to Adapter TP Sensor IAC Valve MAP Sensor 44-62 Knock Sensor to Block 12-16 16.3-21.7 Intake Manifold to Plenum Fuel Rail Fuel Line Connections Fuel Meter Cover Assembly Screws Fuel Inlet and Return Lines ECT Sensor...
Page 493: Exploded Views - 350 Mag Mpi
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Exploded Views - 350 Mag MPI Flame Arrestor And Throttle Body 75828 Earlier Models Cover Washer Nut (1/4-28) Flame Arrestor Bracket Nut (1/4-20) Washer Washer Flame Arrestor Clamp 10 - Throttle Body Assembly 11 - Gasket 12 -...
Page 494: Flame Arrestor And Throttle Body
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Flame Arrestor And Throttle Body Later Models Cover 12 - Screw [5/16-18 x 1-1/4 in. (32 mm)] Washer 13 - Washer Nut (1/4-28) 14 - Throttle Body Adaptor Plate Washer 15 - Gasket Flame Arrestor 16 -...
Page 495: Intake Manifold And Fuel Rail
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Intake Manifold And Fuel Rail 75829 MEFI 1 and MEFI 2 Models Intake Manifold 11 - Fuel Rail Gasket 12 - Elbow Fitting Pipe Plug 13 - Stud (2) Screw [5/16-18 x 1-3/8 in.(35 mm)] 14 - Screw (1/4-20) Fuel Injector...
Page 496: Intake Manifold And Fuel Rail
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Intake Manifold And Fuel Rail 75829 MEFI 3 Models Intake Manifold 11 - Fuel Rail Gasket 12 - Schrader Valve Pipe Plug 13 - Screws (1/4-20 x 1-1/2 in.) Screw [5/16-18 x1-3/8 in. (35 mm)] 14 - MAT Sensor Fuel Injector...
Page 497: Fuel Pressure Relief Procedure
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Fuel Pressure Relief Procedure NOTICE Refer to “Service Precautions,” at front of this section BEFORE proceeding. 1. Disconnect electrical connector at fuel pump. 2. Crank engine for ten seconds (if engine starts allow it run until it stops) to relieve any fuel pressure in the system.
Page 498 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 2. If equipped, remove flame arrestor cover bracket. DO NOT remove the fuel rail stud. 75830 Bracket Nuts and Fuel Rail Stud 3. If equipped, loosen the clamp and remove the flame arrestor. 75828 Throttle Body Clamp...
Page 499 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION 1. Clean flame arrestor in solvent. 2. Wear eye protection. Dry flame arrestor with compressed air. INSTALLATION 1. Replace components as appropriate for your model. Tighten all fasteners securely 75830 75828 Earlier Models...
Page 500: Throttle Body
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 2. Install flame arrestor cover. Secure with washer and locknut. 76365 75831 Typical Connections Flame Arrestor Cover Washer Flame Arrestor Throttle Body NOTICE Refer to “Service Precautions,” at front of this section BEFORE proceeding. REMOVAL 1.
Page 501 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 3. Disconnect the wiring connectors from the IAC valve and the TP sensor. 75788 IAC Valve Connector Throttle Position Sensor Connector 4. Remove the screws (3) retaining the throttle body and remove the throttle body from the adapter.
Page 502 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION IMPORTANT: DO NOT use cleaners containing methyl ethyl ketone. It is not neces- sary for cleaning throttle bore and valve deposits. IMPORTANT: DO NOT allow the TP sensor and IAC valve to come into contact with solvent or cleaner.
Page 503: Throttle Position Sensor
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 3. Connect the harness connectors to the TP sensor and IAC valve. 75788 IAC Valve Connector Throttle Position Sensor Connector 4. Connect the throttle cable to the throttle lever. Refer to SECTION 2 for throttle cable adjustment.
Page 504 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION 1. Clean the surfaces of the TP sensor with a dry cloth. 2. Inspect the sensor for signs of wear or damage. INSTALLATION 1. Apply Loctite 242 to screw threads. Install the TP sensor and dust seal on the throttle body using the screws.
Page 505: Idle Air Control (Iac) Valve
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Idle Air Control (IAC) Valve NOTICE Refer to “Service Precautions,” in front of this section BEFORE proceeding. REMOVAL 1. Remove the flame arrestor, throttle cable and throttle body. 2. Remove the IAC valve from the throttle body. 75657 Screw (2) Idle Air Control (IAC) Valve...
Page 506 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 INSTALLATION IMPORTANT: If installing a new IAC valve, be sure to replace it with an identical part. IAC valve pintle shape and diameter are designed for the specific application. 1. Install new O-ring on IAC valve. 75784 75657 Screw (2)
Page 507: Knock Sensor
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Knock Sensor NOTICE Refer to “Service Precautions,” in front of this section BEFORE proceeding. REMOVAL 1. Disconnect electrical connector at Knock Sensor located just ahead of starter motor. 75678 Starboard Side Shown Knock Sensor Electrical Connector 2.
Page 508: Knock Sensor Module
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Knock Sensor Module 1. Remove the Knock Sensor Module from the electrical box. 75833 Knock Sensor Module Electrical Box 2. Disconnect electrical connector at Knock Sensor (KS) module. CLEANING AND INSPECTION 1.
Page 509: Fuel Pump Relay
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Fuel Pump Relay REMOVAL 1. Remove fuel pump relay from electrical box. 75834 Fuel Pump Relay 2. Disconnect electrical connector and remove fuel pump relay. CLEANING AND INSPECTION IMPORTANT: The fuel pump relay is an electrical component. DO NOT soak in any liq- uid cleaner or solvent;...
Page 510: Electronic Control Module (Ecm)
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 INSTALLATION 1. Attach electrical connector to relay. 2. Place system relay in electrical box. Electronic Control Module (ECM) NOTICE Refer to “Service Precautions,” in front of this section BEFORE proceeding. IMPORTANT: The ECM is a sensitive electrical device, subject to electrostatic damage.
Page 511 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION 1. Clean the exterior of the ECM with a dry cloth being careful to avoid contact with connector pins. 2. Inspect outer surfaces for any obvious damage 3. Visually inspect electrical pins at both ends of ECM for straightness and corrosion. 4.
Page 512: Engine Coolant Temperature (Ect) Sensor
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Engine Coolant Temperature (ECT) Sensor NOTICE Refer to “Service Precautions,” in front of this section BEFORE proceeding. REMOVAL NOTE: Handle the ECT carefully as any damage to it will affect operation of the system. 1.
Page 513: Vacuum And Vent Hose Routing
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Vacuum And Vent Hose Routing 350 Mag MPI Models 75837 Throttle Body Adapter Cool Fuel Assembly Vacuum Hose - Throttle Body Adapter to Fuel Pressure Regulator on Cool Fuel Assembly Vent Hose - PCV Valve to Throttle Body Adapter Vent Hose - Valve Cover Fitting To Flame Arrestor PCV Valve Vacuum Hose - T-Fitting to Plenum...
Page 514: Exploded Views - Black Scorpion
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Exploded Views - Black Scorpion Plenum, Throttle Body And Flame Arrestor 75838 Intake Plenum Hose Gasket Throttle Body Stud 10 - Screw Nut (2) 11 - Flame Arrestor Plenum Screw 12 - Clamp MAP Sensor 13 -...
Page 515: Intake Manifold And Fuel Rails
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Intake Manifold And Fuel Rails 75839 Intake Manifold 10 - O-Ring Intake Gasket (2) 11 - Screen Fuel Rail (2) 12 - Lower Seal Screw 13 - Stud Connector Fittings 14 - Spacer Schrader Valve 15 -...
Page 516: Flame Arrestor
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Fuel Pressure Relief Procedure NOTICE Refer to “Service Precautions,” in front of this section BEFORE proceeding. 1. Disconnect electrical connector at fuel pump. 2. Crank engine for ten seconds (if engine starts allow it run until it stops) to relieve any fuel pressure in the system.
Page 517 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION 1. Clean flame arrestor in solvent. Blow dry with compressed air or allow to air dry completely. 2. Clean crankcase ventilation hoses in solvent. Blow dry with compressed air or allow to air dry completely.
Page 518 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Throttle Body NOTICE Refer to “Service Precautions,” in front of this section BEFORE proceeding. REMOVAL 1. Remove the flame arrestor. 2. Disconnect the throttle cable from the throttle lever. 74838 Throttle Cable Flame Arrestor Index 90-861327--1 OCTOBER 1999...
Page 519 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 3. Disconnect the wiring connectors from the IAC valve and the TP sensor. 75788 Earlier Style Throttle Body IAC Valve Connector Throttle Position Sensor Connector 75777 75778 Later Style Throttle Body Throttle Position Sensor Connector IAC Valve Connector Index...
Page 520: Throttle Body
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 4. Remove the hardware retaining the throttle body and remove the throttle body from the adapter. Refer to “Exploded View.” 75838 Throttle Body Screws Gasket (Single On Earlier Models) NOTE: The later style throttle body uses two gaskets and a plate between the throttle body and the plenum.
Page 521 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION IMPORTANT: DO NOT use cleaners containing methyl ethyl ketone. It is not necessary for cleaning throttle bore and valve deposits. IMPORTANT: DO NOT allow the TP sensor and IAC valve to come into contact with solvent or cleaner.
Page 522 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 2. Place the throttle body on the plenum. Install the screw and nuts (or 3 screws on Earlier Style) and torque to 75 lb-in. (8.5 Nm). 75781 Later Style With Screw And Nuts Throttle Body Screw Nuts...
Page 523 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 75778 Later Style Throttle Body IAC Valve Connector 4. Connect the throttle cable to the throttle lever. Refer to SECTION 2 for throttle cable adjustment. 5. Install the flame arrestor. Index Page 5E-34 90-861327--1 OCTOBER 1999...
Page 524: Plenum
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Plenum REMOVAL 1. Disconnect the throttle cable. 2. Disconnect the harness connector and the vacuum hose from the MAP sensor. The sensor is located on the underside of the plenum on the starboard side. 3.
Page 525 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 5. Torque the fasteners evenly in a diagonal pattern to 150 lb-in. (17Nm). 75710 Screws (6) Plenum Gasket Nuts MAP Sensor Location 6. Place remote control throttle lever in idle position. Attach cable to throttle lever stud. Refer to SECTION 2 for throttle cable adjustment.
Page 526 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Fuel Rails REMOVAL 1. Remove distributor cap. 2. Disconnect fuel lines from aft end fuel rail connector fittings. 75696 Fuel Lines and Connections - Aft View Fuel Rail Connector Fittings Rail-to-Rail Fuel Lines Cool Fuel-to-Fuel Rail Line Distributor Cap 3.
Page 527 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 8. Remove fuel rails. 00000 Typical Fuel Rails Screws (2 Each Side) CLEANING AND INSPECTION 1. Clean fuel rails in solvent and dry with compressed air. 2. Inspect injector cavities for damage that could affect proper sealing of the injectors in the rail.
Page 528 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Fuel Injectors REMOVAL NOTE: Use care in removing fuel injectors to prevent damage to the electrical connector and nozzle. IMPORTANT: The fuel injector is an electrical component. DO NOT soak in any liquid cleaner or solvent, as damage may result.
Page 529: Map Sensor
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 MAP Sensor REMOVAL 1. Disconnect electrical connector at manifold absolute pressure (MAP) sensor. 00000 Plenum Manifold Absolute Pressure (MAP) Sensor Vacuum Hose To Intake Manifold Screws (2) 2. Remove MAP sensor. CLEANING AND INSPECTION 1.
Page 530: Throttle Position Sensor
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Throttle Position Sensor REMOVAL 1. Disconnect electrical connector at throttle position (TP) sensor. 2. Remove TP sensor from throttle body. Remove the dust seal. 75788 Earlier Style Throttle Body Throttle Position (TP) Sensor Harness Screws 75777 Later Style Throttle Body...
Page 531 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 INSTALLATION IMPORTANT: If the TP sensor is to be replaced with a new unit, be sure to secure it in place with the new screws which are included in the service package. 1.
Page 532: Idle Air Control (Iac) Valve
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Idle Air Control (IAC) Valve REMOVAL 1. Remove flame arrestor, throttle cable and throttle body. 2. Disconnect electrical connector at idle air control (IAC) valve. 75788 75788 Earlier Style Throttle Body Later Style Throttle Body Idle Air Control (IAC) Valve Connector Screws...
Page 533 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 2. Install IAC valve on throttle body using screws. Torque to 20 lb-in. (2 Nm). 75784 75657 Earlier Style Throttle Body Later Style Throttle Body Idle Air Control (IAC) Valve Screws 3.
Page 534: Knock Sensor
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Knock Sensor REMOVAL 1. Disconnect electrical connector at Knock Sensor located just ahead of starter motor. 73757 Knock Sensor Harness Connector 2. Remove Knock Sensor from engine block. CLEANING AND INSPECTION 1.
Page 535: Knock Sensor Module
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Knock Sensor Module REMOVAL 1. Remove Knock Sensor Module (KS) from electrical box. 00000 Knock Sensor (KS) Module 2. Disconnect electrical connector at Knock Sensor Module. CLEANING AND INSPECTION 1. Clean the external surfaces of the KS module with a dry cloth. 2.
Page 536: System Relay
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 System Relay REMOVAL 1. Remove system relay from electrical box. 00000 System Relay 2. Disconnect electrical connector and remove relay. IMPORTANT: The system relay is an electrical component. DO NOT soak in any liquid cleaner or solvent;...
Page 537 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION 1. Clean the exterior of the ECM with a dry cloth being careful to avoid contact with connector pins. 2. Inspect outer surfaces for any obvious damage 3. Visually inspect electrical pins at both ends of ECM for straightness and corrosion. 4.
Page 538: Scorpion Models
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Vacuum And Vent Hose Routing Scorpion Models 00000 Throttle Body Adapter Cool Fuel Assembly Vacuum Hose - Forward Fitting On Intake Manifold To Fuel Pressure Regulator on Cool Fuel Assembly Vent Hose - PCV Valve to Throttle Body Adapter Vent Hose - Valve Cover to Flame Arrestor PCV Valve Vent Hose Fitting...
Page 539: Exploded Views - Throttle Body Efi
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Exploded Views - Throttle Body EFI Throttle Body Body And Adapter 76500 75841 Throttle Body Screws (3) Gasket Throttle Body Adapter Screws (4) Gasket Intake Manifold Index Page 5E-50 90-861327--1 OCTOBER 1999...
Page 540 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Throttle Body Assembly 73766 Cap Screw 11 - Body Cover Assembly 12 - Throttle Body To Fuel Meter Body Gasket Fuel Pressure Regulator 13 - Throttle Body Cover Assembly Gasket 14 - Throttle Position (TP) Sensor Upper O-Ring 15 -...
Page 541: Fuel Pressure Relief Procedure
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Fuel Pressure Relief Procedure NOTICE Refer to “Service Precautions,” in front of this section BEFORE proceeding. 1. Disconnect electrical connector at fuel pump. 2. Crank engine for ten seconds (if engine starts allow it run until it stops) to relieve any fuel pressure in the system.
Page 542 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION IMPORTANT: DO NOT immerse the fuel meter cover (with pressure regulator) in cleaner, as damage to the regulator diaphragm and gasket could occur. 1. Inspect pressure regulator seating area for damage. Use a magnifying glass if necessary.
Page 543: Fuel Injectors
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Fuel Injectors NOTICE Refer to “Service Precautions,” at front of this section BEFORE proceeding. REMOVAL NOTE: Use care in removing fuel injectors to prevent damage to the electrical connector and nozzle. IMPORTANT: The fuel injector is an electrical component.
Page 544 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 INSTALLATION 1. Install new lower O-rings on fuel injectors. Lubricate O-rings using a water soap solution. 73766 Fuel Injector Upper O-Ring Lower O-Ring Fuel Filter 2. Install upper O-rings in fuel meter body. Lubricate O-rings with water soap solution. 3.
Page 545: Throttle Body
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Throttle Body REMOVAL CAUTION Ensure that fuel pressure is relieved before removing the fuel inlet and return lines. IMPORTANT: DO NOT allow the TP sensor, fuel pressure regulator, fuel injectors and IAC valve to come into contact with solvent or cleaner.
Page 546 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 INSTALLATION 1. Install fuel injectors and fuel meter body. 2. Install a new gasket on adapter plate. 3. Install throttle body on adapter plate and torque the screws 30 lb-ft (40 Nm). 4.
Page 547: Throttle Body Adapter Plate
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Throttle Body Adapter Plate NOTICE Refer to “Service Precautions,” at front of this section BEFORE proceeding. REMOVAL IMPORTANT: Place a clean shop towel over the intake manifold opening to prevent foreign material from entering the engine. 1.
Page 548: Engine Control Module (Ecm)
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Engine Control Module (ECM) IMPORTANT: The ECM is a sensitive electrical device, subject to electrostatic damage. Therefore, take care not to touch connector pins when removing or installing the module. REMOVAL 1.
Page 549 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 INSTALLATION 1. Mount new ECM to electrical bracket. 2. Connect J1 and J2 electrical connectors to the ECM. 72801 MEFI 1 Shown Electrical Bracket J1- Electrical Connector (Front Connector) J2- Electrical Connector (Rear Connector) Index Page 5E-60 90-861327--1 OCTOBER 1999...
Page 550: Knock Sensor (Ks) Module (Mefi 1 And Mefi 2 Only)
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Knock Sensor (KS) Module (MEFI 1 and MEFI 2 Only) NOTICE Refer to “Service Precautions,” at front of this section BEFORE proceeding. REMOVAL 1. Remove Knock Sensor from electrical bracket. 72801 MEFI 1 Shown Electrical Bracket Knock Sensor (KS) Sensor...
Page 551: Engine Coolant Temperature (Ect) Sensor
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 INSTALLATION 1. Connect electrical connector to the Knock Sensor (KS) Module. 2. Mount KS module to electrical bracket. 72801 MEFI 1 Shown Electrical Bracket Knock Sensor (KS) Sensor Engine Coolant Temperature (ECT) Sensor NOTICE Refer to “Service Precautions,”...
Page 552 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION 1. Clean with a dry cloth, removing any excess sealant from the base threads. 2. Look for evidence of any physical damage to base or connector surfaces of the ECT. INSTALLATION 1.
Page 553 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Throttle Position (TP) Sensor NOTICE Refer to “Service Precautions,” at front of this section BEFORE proceeding. REMOVAL 1. Disconnect electrical connector at throttle position (TP) sensor. 2. Remove TP sensor from throttle body. 73758 Throttle Body Throttle Position (TP) Sensor...
Page 554 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Idle Air Control (IAC) Valve NOTICE Refer to “Service Precautions,” at front of this section BEFORE proceeding. REMOVAL 1. Remove flame arrestor, throttle cable and throttle body. 2. Disconnect electrical connector at idle air control (IAC) valve. 73754 Throttle Body Idle Air Control (IAC) Valve...
Page 555 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 INSTALLATION IMPORTANT: If installing a new IAC valve, be sure to replace it with the correct IAC valve pintle shape and diameter are designed for the specific application. 1. Install new O-ring on IAC valve. 73766 Throttle Body Idle Air Control (IAC) Valve...
Page 556 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 Knock Sensor NOTICE Refer to “Service Precautions,” at front of this section BEFORE proceeding. REMOVAL 1. Disconnect electrical connector at Knock Sensor located just ahead of starter motor. 73757 Knock Sensor 2.
Page 557 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 Vacuum And Vent Hose Routing Throttle Body EFI Models 00000 Plenum Cool Fuel Assembly Diaphragm Rupture Hose - Fuel Pressure Regulator on Cool Fuel Assembly To Side of Flame Arrestor Vent Hose - PCV Valve to Throttle Body Adapter PCV Valve Vent Hose - Valve Cover Fitting To Flame Arrestor Valve Cover Fitting...
Page 558 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index 90-861327--1 OCTOBER 1999 Page 5E-69...
Page 559 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 5E-70 90-861327--1 OCTOBER 1999...
Page 560 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 FUEL SYSTEM Section 5E - Fuel Injection Disassembly And Reassembly Table of Contents Service Precautions ....5E-2 Exploded Views - MX 6.2 Black Scorpion 5E-20 Specifications...
Page 561 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Service Precautions WARNING Always disconnect battery cables from battery BEFORE working on fuel system to prevent fire or explosion. WARNING Be careful when cleaning flame arrestor and crankcase ventilation hose; gasoline is extremely flammable and highly explosive under certain conditions.
Page 562: Lubricants / Sealants / Adhesives
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Specifications Torque Specifications Fastener Location lb-in. lb-ft Throttle Body Screws Throttle Body on Adapter Throttle Body on Plenum TP Sensor And Dust Seal IAC Valve MAP Sensor 44-62 Knock Sensor 12-16 16-22 Black Scorpion Plenum...
Page 563: Exploded Views - Mx 6.2L Mpi
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Exploded Views - MX 6.2L MPI Flame Arrestor And Throttle Body NOTE: The 6.2L engine may be equipped with one of two covers. Both covers are shown below, but most pictures will show the early model cover. 77439 Cover 12 -...
Page 564: Intake Manifold And Fuel Rail
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Intake Manifold And Fuel Rail 75829 Intake Manifold 11 - Fuel Rail Gasket 12 - Schrader Valve Pipe Plug 13 - Screws (1/4-20 x 1-1/2 in.) Screw [5/16-18 x1-3/8 in. (35 mm)] 14 - MAT Sensor Fuel Injector...
Page 565: Flame Arrestor
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Fuel Pressure Relief Procedure NOTICE Refer to “Service Precautions,” at front of this section BEFORE proceeding. 1. Disconnect electrical connector at fuel pump. 2. Crank engine for ten seconds (if engine starts allow it run until it stops) to relieve any fuel pressure in the system.
Page 566 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 2. Loosen the nut and remove the flame arrestor. 76501 Flame Arrestor CLEANING AND INSPECTION 1. Clean flame arrestor in solvent. 2. Wear eye protection. Dry flame arrestor with compressed air. INSTALLATION 1.
Page 567: Throttle Body
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 2. Install flame arrestor cover. Secure with washer and locknut. 75831 76365 Flame Arrestor Cover Washer Flame Arrestor Throttle Body NOTICE Refer to “Service Precautions,” at front of this section BEFORE proceeding. REMOVAL 1.
Page 568 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 4. Remove the screws (3) retaining the throttle body and remove the throttle body from the adapter. Refer to “Exploded View”. 75828 Adapter Gasket Throttle Body Screws IMPORTANT: Insert a clean shop towel into the opening of the plenum to prevent for- eign material from entering the engine.
Page 569 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION IMPORTANT: DO NOT use cleaners containing methyl ethyl ketone. It is not neces- sary for cleaning throttle bore and valve deposits. IMPORTANT: DO NOT allow the TP sensor and IAC valve to come into contact with solvent or cleaner.
Page 570 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 3. Connect the harness connectors to the TP sensor and IAC valve. 75788 IAC Valve Connector Throttle Position Sensor Connector 4. Connect the throttle cable to the throttle lever. Refer to SECTION 2 for throttle cable adjustment.
Page 571 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION 1. Clean the surfaces of the TP sensor with a dry cloth. 2. Inspect the sensor for signs of wear or damage. INSTALLATION 1. Apply Loctite 242 to screw threads. Install the TP sensor and dust seal on the throttle body using the screws.
Page 572: Idle Air Control (Iac) Valve
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Idle Air Control (IAC) Valve NOTICE Refer to “Service Precautions,” in front of this section BEFORE proceeding. REMOVAL 1. Remove the flame arrestor, throttle cable and throttle body. 2. Remove the IAC valve from the throttle body. 75657 Screw (2) Idle Air Control (IAC) Valve...
Page 573 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 INSTALLATION IMPORTANT: If installing a new IAC valve, be sure to replace it with an identical part. IAC valve pintle shape and diameter are designed for the specific application. 1.
Page 574: Knock Sensor
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Knock Sensor NOTICE Refer to “Service Precautions” in front of this section BEFORE proceeding. REMOVAL 1. Disconnect electrical connector at knock sensor located just ahead of starter motor. 75678 Starboard Side Shown Knock Sensor Electrical Connector...
Page 575: Fuel Pump Relay
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Knock Sensor Module 1. Remove the knock sensor module from the electrical bracket. 2. Disconnect electrical connector at knock sensor (KS) module. CLEANING AND INSPECTION 1. Clean the external surfaces of the KS module with a dry cloth. 2.
Page 576: System Relay
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 System Relay REMOVAL 1. Remove system relay from electrical bracket. System Relay 2. Disconnect electrical connector and remove relay. CLEANING AND INSPECTION IMPORTANT: The system relay is an electrical component. DO NOT soak in any liquid cleaner or solvent;...
Page 577: Engine Coolant Temperature
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 INSTALLATION 1. Mount new ECM to electrical bracket using screws and washers. 2. Connect J1 and J2 electrical connectors to the ECM. DO NOT touch connector pins when installing. Engine Coolant Temperature (ECT) Sensor NOTICE Refer to “Service Precautions”...
Page 578: Mx 6.2 Mpi Models
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Vacuum And Vent Hose Routing MX 6.2 MPI Models 75837 Throttle Body Adapter Cool Fuel Assembly Vacuum Hose - Throttle Body Adapter to Fuel Pressure Regulator on Cool Fuel Assembly Vent Hose - PCV Valve to Throttle Body Adapter Vent Hose - Valve Cover Fitting To Flame Arrestor...
Page 579: Plenum, Throttle Body And Flame Arrestor
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Exploded Views - MX 6.2 Black Scorpion Plenum, Throttle Body And Flame Arrestor 75838 Intake Plenum Hose Gasket Throttle Body Stud 10 - Screw Nut (2) 11 - Flame Arrestor Plenum Screw 12 - Clamp...
Page 580: Intake Manifold And Fuel Rails
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Intake Manifold And Fuel Rails 75839 Intake Manifold 10 - O-Ring Intake Gasket (2) 11 - Screen Fuel Rail (2) 12 - Lower Seal Screw 13 - Stud Connector Fittings 14 - Spacer Schrader Valve...
Page 581: Fuel Pressure Relief Procedure
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Fuel Pressure Relief Procedure NOTICE Refer to “Service Precautions” in front of this section BEFORE proceeding. 1. Disconnect electrical connector at fuel pump. 2. Crank engine for ten seconds (if engine starts allow it run until it stops) to relieve any fuel pressure in the system.
Page 582 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION 1. Clean flame arrestor in solvent. Blow dry with compressed air or allow to air dry completely. 2. Clean crankcase ventilation hoses in solvent. Blow dry with compressed air or allow to air dry completely.
Page 583: Throttle Body
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Throttle Body NOTICE Refer to “Service Precautions” in front of this section BEFORE proceeding. REMOVAL 1. Remove the flame arrestor. 2. Disconnect the throttle cable from the throttle lever. 74838 Throttle Cable Flame Arrestor...
Page 584 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 4. Remove the hardware retaining the throttle body and remove the throttle body from the adapter. Refer to “Exploded View.” 75783 Throttle Body Gaskets Plate IMPORTANT: Insert a clean shop towel into the opening of the plenum to prevent foreign material from entering the engine.
Page 585 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION IMPORTANT: DO NOT use cleaners containing methyl ethyl ketone. It is not necessary for cleaning throttle bore and valve deposits. IMPORTANT: DO NOT allow the TP sensor and IAC valve to come into contact with solvent or cleaner.
Page 586 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 3. Connect the harness connectors to the TP sensor and IAC valve. 75777 TP Sensor Connector 75778 IAC Valve Connector 4. Connect the throttle cable to the throttle lever. Refer to SECTION 2 for throttle cable adjustment.
Page 587: Plenum
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Plenum REMOVAL 1. Disconnect the throttle cable. 2. Disconnect the harness connector and the vacuum hose from the MAP sensor. The sensor is located on the underside of the plenum on the starboard side. 3.
Page 588 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 5. Torque the fasteners evenly in a diagonal pattern to 150 lb-in. (17 Nm). 75710 Screws (6) Plenum Gasket Nuts MAP Sensor Location 6. Place remote control throttle lever in idle position. Attach cable to throttle lever stud. Refer to SECTION 2 for throttle cable adjustment.
Page 589: Fuel Rails
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Fuel Rails REMOVAL 1. Remove distributor cap. 2. Disconnect fuel lines from aft end fuel rail connector fittings. 75696 Fuel Lines and Connections - Aft View Fuel Rail Connector Fittings Rail-to-Rail Fuel Lines Cool Fuel-to-Fuel Rail Line Distributor Cap...
Page 590 FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 8. Remove fuel rails. 00000 Typical Fuel Rails Screws (2 Each Side) CLEANING AND INSPECTION 1. Clean fuel rails in solvent and dry with compressed air. 2. Inspect injector cavities for damage that could affect proper sealing of the injectors in the rail.
Page 591: Fuel Injectors
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Fuel Injectors REMOVAL NOTE: Use care in removing fuel injectors to prevent damage to the electrical connector and nozzle. IMPORTANT: The fuel injector is an electrical component. DO NOT soak in any liquid cleaner or solvent, as damage may result.
Page 592: Manifold Absolute Pressure (Map) Sensor
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 MAP Sensor REMOVAL 1. Disconnect electrical connector at manifold absolute pressure (MAP) sensor. 00000 Plenum Manifold Absolute Pressure (MAP) Sensor Vacuum Hose To Intake Manifold Screws (2) 2. Remove MAP sensor. CLEANING AND INSPECTION 1.
Page 593: Throttle Position (Tp) Sensor
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Throttle Position Sensor REMOVAL 1. Disconnect electrical connector at throttle position (TP) sensor. 2. Remove TP sensor from throttle body. Remove the dust seal. 75777 Throttle Position (TP) Sensor Harness Screws CLEANING AND INSPECTION 1.
Page 594: Idle Air Control (Iac) Valve
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Idle Air Control (IAC) Valve REMOVAL 1. Remove flame arrestor, throttle cable and throttle body. 2. Disconnect electrical connector at idle air control (IAC) valve. 75788 Idle Air Control (IAC) Valve Connector Screws 3.
Page 595 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 2. Install IAC valve on throttle body using screws. Torque to 20 lb-in. (2 Nm). 75784 Idle Air Control (IAC) Valve Screws 3. Connect electrical connector to IAC valve. 75788 Idle Air Control (IAC) Valve Connector 4.
Page 596: Knock Sensor
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Knock Sensor REMOVAL 1. Disconnect electrical connector at knock sensor located just ahead of starter motor. 73757 Knock Sensor Harness Connector 2. Remove knock sensor from engine block. CLEANING AND INSPECTION 1.
Page 597: Knock Sensor Module
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Knock Sensor Module REMOVAL 1. Remove knock sensor module (KS) from electrical box. 00000 Knock Sensor (KS) Module 2. Disconnect electrical connector at knock sensor module. CLEANING AND INSPECTION 1.
Page 598: Fuel Pump Relay
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Fuel Pump Relay REMOVAL 1. Remove fuel pump relay from electrical box. 00000 Fuel Pump Relay 2. Disconnect electrical connector and remove fuel pump relay. IMPORTANT: The fuel pump relay is an electrical component. DO NOT soak in any liquid cleaner or solvent;...
Page 599 FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Engine Control Module IMPORTANT: The ECM is a sensitive electrical device, subject to electrostatic damage. Therefore, take care not to touch connector pins when removing or installing the module. REMOVAL 1.
Page 600: Engine Coolant Temperature Sensor
FUEL INJECTION DISASSEMBLY AND REASSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 CLEANING AND INSPECTION 1. Clean the exterior of the ECM with a dry cloth being careful to avoid contact with connector pins. 2. Inspect outer surfaces for any obvious damage 3.
Page 601: Mx 6.2 Black Scorpion Models
FUEL INJECTION DISASSEMBLY AND REASSSEMBLY SUPPLEMENT TO SERVICE MANUAL NUMBER 24 Vacuum And Vent Hose Routing MX 6.2 Black Scorpion Models 00000 Throttle Body Cool Fuel Assembly Vacuum Hose - Forward Fitting On Intake Manifold To Fuel Pressure Regulator on Cool Fuel Assembly Vent Hose - PCV Valve to Throttle Body Vent Hose - Valve Cover to Flame Arrestor PCV Valve...
Page 602 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 FUEL SYSTEMS Section 5F - Fuel Injection System Troubleshooting Table of Contents Scan Tool Normal Specifications (Idle / Warm Detonation / Spark Knock Symptom . . . 5F-11 Engine / Closed Throttle / Neutral) .
Page 603 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Scan Tool Normal Specifications (Idle / Warm Engine / Closed Throttle / Neutral) Scan Position Units Displayed Typical Data Value 600-700 rpm Desired rpm 600 or 650 rpm - Depends on Model °...
Page 604: Before Starting
FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Important Preliminary Checks Before Starting Before using this section you should have performed the “On-Board Diagnostic (OBD) Sys- tem Check” in the “General System Diagnostics” section and determined that: • The ECM and/or MIL (Malfunction Indicator Lamp) are operating correctly. •...
Page 605 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Intermittents IMPORTANT: Problem may or may not turn “ON” the Malfunction Indicator Lamp (MIL) or store a DTC. DO NOT use the Diagnostic Trouble Code (DTC) tables for inter- mittent problems. The fault must be present to locate the problem. Most intermittent problems are caused by faulty electrical connections or wiring.
Page 606 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Hard Start Symptom Step Action PROCEED TO Definition: Engine cranks OK, but does not start for a long time. Does eventually run, or may start but immediately dies. Was the “On-Board Diagnostic” (OBD) System Check performed? Step 2 Does the driver know the correct starting...
Page 607 2. If all procedures have been completed and no malfunctions have been found, review/ inspect the following: • Visual/physical inspection. Contact • Scan tool data. MerCruiser • All electrical connections within a sus- Customer pected circuit and/or system. Service Index...
Page 608 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Surges and/or Chuggles Symptom Step Action PROCEED TO Definition: Engine power variation under steady throttle or cruise. Feels like the engine speeds up and slows down with no change in the throttle lever position. Was the “On-Board Diagnostic”...
Page 609 2. If all procedures have been completed and no malfunctions have been found, review/ inspect the following: • Visual/physical inspection. • Scan tool data. Contact • All electrical connections within a sus- MerCruiser pected circuit and/or system. Customer Service Was a problem found? Index Page 5F-8...
Page 610 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Lack of Power, Sluggish or Spongy Symptom Step Action PROCEED TO Definition: Engine delivers less than expected power. Little or no increase in speed when throttle lever is advanced part way. Was the “On-Board Diagnostic” (OBD) System Check performed? Step 2 If possible, compare engine performance with...
Page 611 2. When all procedures have been completed and no malfunctions are found, review/in- spect the following: • Visual/physical inspection. • Scan tool data. Contact • All connections within a suspected circuit MerCruiser and/or system. Customer Service Was a problem found? Index Page 5F-10...
Page 612 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Detonation / Spark Knock Symptom Step Action PROCEED TO Definition: A mild to severe ping, usually worse under acceleration. The engine makes sharp metallic knocks that change with throttle opening. Was the “On-Board Diagnostic” (OBD) System Check performed? Step 2 Visual/ Physical...
Page 613 2. If all procedures have been completed and no malfunctions have been found, review/ inspect the following: • Visual/physical inspection. • Scan tool data. Contact • All electrical connections within a sus- MerCruiser pected circuit and/or system. Customer Service Was a problem found? Index Page 5F-12...
Page 614 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Hesitation, Sag, Stumble Symptom Step Action PROCEED TO Definition: Momentary lack of response as the throttle lever is advanced. Can occur at all engine speeds. Usually most severe when first starting out. May cause engine to stall if severe enough.
Page 615 • Visual/physical inspection. • Scan tool data. Contact • All electrical connections within a sus- MerCruiser pected circuit and/or system. Customer Go to OBD Service Was a problem found? System Check...
Page 616 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Cuts Out, Misses Symptom Step Action PROCEED TO Definition: Steady pulsation or jerking that follows engine speed, usually more pronounced as engine load increases. The exhaust has a steady spitting sound at idle, low speed or on hard acceleration for fuel starvation that can cause engine to cut out.
Page 617 • Visual/physical inspection. • Scan tool data. • All electrical connections within a sus- Contact pected circuit and/or system. MerCruiser 3. If a problem is found, repair as necessary. Customer Service Was a problem found? Index Page 5F-16...
Page 618 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Rough, Unstable, or Incorrect Idle, Stalling Symptom Step Action PROCEED TO Definition: Engine runs unevenly at idle. If severe, the engine or vessel may shake. Engine idle speed may vary in rpm. Either condition may be severe enough to stall the engine.
Page 619 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Rough, Unstable, or Incorrect Idle, Stalling Symptom (Continued) Step Action PROCEED TO 1. Disconnect all injector harness connectors and install an injector test light J 34730-2 between the harness terminal connector of each injector.
Page 620 2. If all procedures have been completed and no malfunctions have been found, review/ inspect the following: • Visual/physical inspection. • Scan tool data. Contact • All electrical connections within a sus- MerCruiser pected circuit and/or system. Customer Service Was a problem found? Index 90-861327--1 OCTOBER 1999...
Page 621 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Poor Fuel Economy Symptom Step Action PROCEED TO Definition: Fuel economy is noticeably lower than expected. Also, economy is noticeably lower than it was on this engine at one time. Was the “On-Board Diagnostic” (OBD) System Check performed? Step 2 Was visual/physical check performed?
Page 622 2. When all procedures have been completed and no malfunctions are found, review/in- spect the following: • Visual/physical inspection. • Scan tool data. Contact • All connections within a suspected circuit MerCruiser and/or system. Customer Service Was a problem found? Index 90-861327--1 OCTOBER 1999...
Page 623 • Visual physical inspection. • Scan tool data. Contact • All electrical connections within a MerCruiser suspected circuit and/or system. Customer Service Was a problem found? Index Page 5F-22 90-861327--1 OCTOBER 1999...
Page 624 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Backfire Symptom Step Action PROCEED TO Definition: Fuel ignites in the intake manifold, or in the exhaust system, making loud popping noise. Was the “On-Board Diagnostic” (OBD) System Check performed? Step 2 Was visual/physical check performed? Visual/ Physical Step 3...
Page 625 2. If all procedures have been completed and no malfunctions have been found, review/ inspect the following: • Visual/physical inspection. • Scan tool data. Contact • All electrical connections within a sus- MerCruiser pected circuit and/or system. Customer Service Was a problem found? Index Page 5F-24...
Page 626 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index 90-861327--1 OCTOBER 1999 Page 5F-25...
Page 627 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 5F-26 90-861327--1 OCTOBER 1999...
Page 628 DIAGNOSTICS SERVICE MANUAL NUMBER 24 FUEL SYSTEMS Section 5G - Diagnostics Table of Contents Special Tools ..... . . 5G-2 Clearing Trouble Codes .
Page 629 Allows multi-meter connections with wiring J-35616 Adapter harness. Displays problem codes stored in the ECM. It also allows monitoring of various MerCruiser Scan circuits and components in the fuel injec- 94050m Tool Version 3.4 tion system. Allows for test firing injectors. (English) Tool can read MEFI 1, MEFI 2 and MEFI 3 ECM.
Page 630 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Special Tools (cont’d) NOTE: The High Impedance Multimeter that comes with the existing Outboard 2 Cycle EFI Tester, P/N 91–11001A2 meets the requirements listed above. NOTE: Quicksilver Digital Tachometer / Multi–Meter (DMT 2000) P/N 91–854009A1, meets the requirements listed above.
Page 631 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Diagnostic Circuit Check IMPORTANT: All references to Scan Tool work with either the Quicksilver Digital Diag- nostic Tool or the Rinda Scan Tool. The Diagnostic Circuit Check is an organized approach to identifying a problem created by an electronic engine control system malfunction.
Page 632: Diagnostic Trouble Codes
DIAGNOSTICS SERVICE MANUAL NUMBER 24 Diagnostic Trouble Codes Code Number Code Description MEFI Code 14 (ECT) Engine Coolant Temperature - Low Temperature Indicated Code 15 (ECT) Engine Coolant Temperature - High Temperature Indicated Code 21 (TP) Throttle Position Sensor - Signal Voltage High Code 22 (TP) Throttle Position Sensor - Signal...
Page 633 DIAGNOSTICS SERVICE MANUAL NUMBER 24 ECM Connector and EFI Symptoms Chart The following charts will aid in diagnosis of symptoms. These voltages were derived from a known good engine. The voltages shown were done with the electrical system intact and operational.
Page 634 DIAGNOSTICS SERVICE MANUAL NUMBER 24 J-1 Circuits with MEFI 1 and MEFI 2 (Continued) Normal Voltage Wire Possible Symptoms Func- Ignition Engine Color tion Running Knock Poor Fuel Economy, Poor J1-1 9.5V 9.5V Sensor Performance Detonation 1.95V 1.95V Poor Performance, Exhaust Odor, J1-2 Signal Rough Idle rpm Reduction...
Page 635 DIAGNOSTICS SERVICE MANUAL NUMBER 24 J-2 Circuits with MEFI 1 and MEFI 2 J-2 Rear 32 Pin Output Connector Shaded Area Denotes Pin Connector Location Used On Terminal Normal Voltage Wire Possible Symptoms Func- Ignition Engine Color tion Running Injector J2-5 None Rough Idle, Lack Of Power, Stall...
Page 636 DIAGNOSTICS SERVICE MANUAL NUMBER 24 J-2 Circuits with MEFI 1 and MEFI 2 (Continued) Normal Voltage Wire Possible Symptoms Func- Ignition Engine Color tion Running Fuel BLK/ Rough Running, Poor Idle, Lack J2-20 None Injector Of Performance (NOTE 5) (NOTE 5) Ground Injector Rough Idle, Lack Of Power,...
Page 637 DIAGNOSTICS SERVICE MANUAL NUMBER 24 J-1 Circuits with MEFI 3 J-1 Front Pin 32 Pin Input Connector Shaded Area Denotes Pin Connector Location Used On Terminal Normal Voltage Wire Possible Symptoms Func- Ignition Engine Color tion Running Injector Rough Idle, Lack Of Power, Stal- J1-1 None Driver...
Page 638 DIAGNOSTICS SERVICE MANUAL NUMBER 24 J-1 Circuits with MEFI 3 (Continued) Normal Voltage Wire Possible Symptoms Func- Ignition Engine Color tion Running Fuel Pump J1-23 None No Start GRN/ (NOTES Relay 1&5) Driver Ignition TAN/ J1-24 4.5V Lack Of Power, Fixed Timing Control (NOTE 5) Bypass...
Page 639 DIAGNOSTICS SERVICE MANUAL NUMBER 24 J-2 Circuits with MEFI 3 J-2 Rear 32 Pin Output Connector Shaded Area Denotes Pin Connector Location Used On Terminal Normal Voltage Wire Possible Symptoms Func- Ignition Engine Color tion Running J2-1 Battery None No Start Sensor High Idle, Rough Idle, Poor Per- J2-3...
Page 640 DIAGNOSTICS SERVICE MANUAL NUMBER 24 J-2 Circuits with MEFI 3 (Continued) Normal Voltage Wire Possible Func- Ignition Engine Color Symptoms tion Running Master/ Lack Of Data From Other En- J2-21 None Slave gine (Dual Engine Only) Diag- BLK/ Incorrect Idle, Poor Perfor- J2-22 None nostic...
Page 641 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Wiring System Diagrams MEFI 1 and MEFI 2 INJECTOR DRIVER J2-21 467 DK BLU INJECTORS - ONE IF EFI, FOUR IF MPI (INJECTORS 2, 3, 5, 8 - IF FOUR) 450 BLK/WHT INJECTOR GROUND J2-15 TO INJECTOR FUSE 439 PNK/BLK J2-20...
Page 642 DIAGNOSTICS SERVICE MANUAL NUMBER 24 MEFI 1 and MEFI 2 (Continued) SHIFT CUTOUT SWITCH (MEFI 2 ONLY) BRAVO REQUIRES JUMPER PLUG SHIFT INTERRUPT J1-19 923 WHT 150 BLK J1-13 SENSOR GROUND 813 BLK THROTTLE POSITION 417 DK BLU J1-10 SENSOR SIGNAL +5 VOLT 416 GRY J1-15...
Page 643 DIAGNOSTICS SERVICE MANUAL NUMBER 24 MEFI 1 and MEFI 2 (Continued) J1-14 ECM GROUND 450 BLK/WHT J1-30 ECM GROUND 450 BLK/WHT IC MODULE SHIFT CUTOUT SWITCH (MEFI 1 ONLY) BRAVO REQUIRES JUMPER PLUG J2-23 IGNITION CONTROL 423 WHT 423 WHT DISTRIBUTOR J2-8 430 PUR/WHT...
Page 644 DIAGNOSTICS SERVICE MANUAL NUMBER 24 MEFI 1 and MEFI 2 (Continued) TO FUEL PUMP RELAY TO IGN COIL B+ TO INJECTORS 150 BLK TO KEY SWITCH 3 PNK TO BATTERY POSITIVE (+) 902 RED 439 PNK/BLK IGNITION FEED 2 RED J1-11 INJ/ECM FUSE 10A SYSTEM/IGNITION RELAY...
Page 645 DIAGNOSTICS SERVICE MANUAL NUMBER 24 MEFI 3 INJECTORS - ONE IF EFI, FOUR IF MPI (INJECTORS 2, 3, 5, 8 - IF FOUR) From INJ/ J1-1 467 DK BLU FUSE 10 AMP 439 PNK INJECTORS - ONE IF EFI, FOUR IF MPI (INJECTORS 1, 4, 6, 7 - IF FOUR) 468 DK GRN J1-17...
Page 646 DIAGNOSTICS SERVICE MANUAL NUMBER 24 MEFI 3 (Continued) INTAKE AIR TEMPERATURE 472 TAN J2-30 INTAKE AIR (IAT) SENSOR SIGNAL TEMPERATURE (IAT) 813 BLK 813 BLK J2-3 SENSOR GROUND 813 BLK 813 BLK 417 DK BLU J2-26 (TP) 416 GRY J2-4 FUEL PRES- FUEL PRESSURE 475 GRN...
Page 647 DIAGNOSTICS SERVICE MANUAL NUMBER 24 MEFI 3 With Mercury Distributor TO FUEL PUMP RELAY FUSE BATTERY 440 0RN J2-1 FEED 2 RED ECM BAT FUSE/ 440 0RN TO DLC DLC 15A CONNECTOR SYSTEM/IGNITION RELAY 2 RED IGN / INJ FUSE 902 RED 2 RED 439 PNK...
Page 648 DIAGNOSTICS SERVICE MANUAL NUMBER 24 MEFI 3 With GM EST Distributor TO FUEL PUMP RELAY FUSE BATTERY 440 0RN J2-1 FEED 2 RED ECM BAT FUSE/ 440 0RN TO DLC TO DLC DLC 15A CONNECTOR CONNECTOR SYSTEM/IGNITION RELAY SYSTEM/IGNITION RELAY 2 RED IGN / INJ FUSE 902 RED...
Page 649 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Injector Balance Test (Multi-Port Models) Test Procedure The injector balance tester is a tool used to turn the injector ON for a precise amount of time, thus spraying a measured amount of fuel into the manifold. This causes a drop in fuel rail pressure that we can record and compare between each injector.
Page 650 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Test Example 300ms Example Cylin- 1st. 38 psi 38 psi 38 psi 38 psi 38 psi 38 psi 38 psi 38 psi Reading (262 kPa) (262 kPa) (262 kPa) (262 kPa) (262 kPa) (262 kPa) (262 kPa) (262 kPa) 19 psi...
Page 651 DIAGNOSTICS SERVICE MANUAL NUMBER 24 General Diagnostic Tests On-Board Diagnostic (OBD) System Check MEFI 1 MEFI 3 MEFI 2 461 ORN/BLK or ORN J1-18 J1-32 J1-14 J1-4 450 BLK/WHT or BLK TO ECM 15A J1-5 450 BLK/WHT or BLK BATTERY FUSE 450 BLK/WHT or BLK CONNECTOR...
Page 652 DIAGNOSTICS SERVICE MANUAL NUMBER 24 On-Board Diagnostic (OBD) System Check Step Action PROCEED TO Are you using a Scan Tool? Step 2. Step 6. a. Ignition OFF. b. Install a scan tool. Chart Step 3. c. Ignition ON. d. Attempt to display ECM data with the scan tool. Does The Scan Tool Display ECM Data? Attempt to start the engine.
Page 653 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-1 (1 of 2): No MIL or No DLC Data MEFI 1 MEFI 3 MEFI 2 461 ORN/BLK or ORN J1-18 J1-32 J1-14 J1-4 450 BLK/WHT or BLK TO ECM 15A J1-5 450 BLK/WHT or BLK BATTERY FUSE 450 BLK/WHT or BLK...
Page 654 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-1 (2 of 2): No MIL or No DLC Data Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? a. Remove CodeMate Tester or Scan Tool. b. Ignition ON, engine OFF. Step 3.
Page 655 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-2 (1 of 2): MIL ON Steady - Will Not Flash DTC 12 MEFI 1 MEFI 3 MEFI 2 461 ORN/BLK or ORN J1-18 J1-32 J1-14 J1-4 450 BLK/WHT or BLK TO ECM 15A J1-5 450 BLK/WHT or BLK BATTERY...
Page 656 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-2 (2 of 2): MIL ON Steady - Will Not Flash DTC 12 Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? a. Ignition ON, engine OFF. Step 9. Step 3.
Page 657 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-3 (1 of 2): Engine Cranks But Will Not Run MEFI 1 MEFI 3 MEFI 2 467 DK BLU J2-21 J1-1 INJECTORS - ONE IF EFI, FOUR IF MPI (INJECTORS 2, 3, 5, 8 - IF FOUR) TO INJECTOR FUSE 439 PNK/BLK OR PNK...
Page 658 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-3 (2 of 2): Engine Cranks But Will Not Run Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? a. Key OFF for minimum of 10 seconds. b. Key ON. Chart Step 3.
Page 659 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-4 (1 of 2): Fuel System Diagnosis FUEL SHUT-OFF TOOL 75752 CIRCUIT DESCRIPTION: When the ignition is turned ON, the Engine Control Module (ECM) will turn the fuel pump ON for 2 seconds. During engine cranking, the ECM will turn ON the fuel pump. It will remain ON as long as the engine is cranking or running, and the ECM is receiving ignition reference pulses.
Page 660 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-4 (2 of 2): Fuel System Diagnosis Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? Install fuel pressure gauge. Ignition OFF. Ignition ON. Fuel pump will run for about 2 seconds. Note fuel Step 3.
Page 661 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-5 (1 of 2): Fuel System Electrical Test FUEL PUMP RELAY FUSE SYSTEM 902 RED 339 PNK/BLK OR PNK RELAY MEFI 1 MEFI 3 MEFI 2 FUEL PUMP J2-9 J1-23 465 DK GRN/WHT RELAY 450 BLK/WHT 450 BLK/WHT OR BLK...
Page 662 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-5 (2 of 2): Fuel System Electrical Test Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? a. Ignition OFF. b. Remove fuel pump relay. c. Ignition ON. Step 3. Step 6.
Page 663 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-6 (1 of 2): EFI System/Ignition Relay Check IGNITION CIRCUIT BREAKER 90 AMP FUSE 902 RED TO ECM TO FUEL PUMP RELAY TO IGN COIL INJ/ECM/KS MODULE CIRCUIT DESCRIPTION: Battery voltage is constantly supplied to terminal “30” of the system relay. When the ignition switch is moved to the “RUN”...
Page 664 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-6 (2 of 2): EFI System/Ignition Relay Check Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? a. Ignition OFF. b. Remove EFI system relay connector. c. Ignition ON. Step 3.
Page 665 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-7 (1 of 6): Ignition System Check MEFI 1, MEFI 2 AND MEFI 3 BLACK SCORPION: IC MODULE DISTRIBUTOR MEFI 1 MEFI 3 MEFI 2 902 RED COIL J2-23 J1-10 J2-8 J2-10 3 PNK J2-24 J1-24 J2-6...
Page 666 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-7 (2 of 6): Ignition System Check MEFI 3 (EXCEPT BLACK SCORPION) DISTRIBUTOR WHT/GRN WHT/RED MEFI 1 MEFI 3 MEFI 2 439 PNK J2-10 430 PPL/WHT 902 RED 121 WHT 121 WHT J1-2 – IGNITION COIL TEMP SENDER...
Page 667 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-7 (3 of 6): Ignition System Check DIAGNOSTIC AIDS: An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Check for the following items: •...
Page 668 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-7 (4 of 6): Ignition System Check Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? a. Check spark plug wires for open circuits, cracks in insulation, or improper seating of terminals at spark plugs, distributor cap, and coil tower before proceeding with this table.
Page 669 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-7 (5 of 6): Ignition System Check Step Action PROCEED TO a. Disconnect distributor 4-wire connector. b. Remove distributor cap. c. Disconnect pick-up coil connector from the distributor ignition control module. d. Connect D\/OM to CKT 121 tach terminal at the 5-way or 6-way harness connector and ground.
Page 670 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-7 (6 of 6): Ignition System Check Step Action PROCEED TO With key in RUN position, measure voltage at positive (+) Chart terminal on ignition coil. Step 25. A–6 Is Voltage Greater Than 10 Volts? Unplug WHT/RED bullet connectors from distributor and measure voltage on CKT 439 from harness.
Page 671 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-8 (1 of 2): Idle Air Control (IAC) Functional Test MEFI 1 MEFI 3 MEFI 2 J2-28 J1-28 441 BRN OR BLU/WHT J2-13 J1-12 442 RED OR BLU/BLK IDLE AIR CONTROL 443 YEL OR GRN/WHT J2-14 J1-11 (IAC) VALVE...
Page 672 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Chart A-8 (2 of 2): Idle Air Control (IAC) Functional Test Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? a. Engine should be at normal operating temperature. b. Start engine and allow idle to stabilize. c.
Page 673 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Discrete Input Circuit Check - Non-Scan Only (1 of 5) MEFI 1, MEFI 2 AND BLACK SCORPION MEFI 3 IC MODULE DISTRIBUTOR MEFI 1 MEFI 3 MEFI 2 902 RED COIL J2-23 J1-10 J2-8 J2-10 3 PNK J2-24 J1-24...
Page 674 DIAGNOSTICS SERVICE MANUAL NUMBER 24 MEFI 3 (EXCEPT BLACK SCORPION) DISTRIBUTOR WHT/GRN WHT/RED MEFI 1 MEFI 3 MEFI 2 439 PNK J2-10 430 PPL/WHT 902 RED 121 WHT 121 WHT J1-2 – IGNITION COIL TEMP SENDER 121 WHT MEFI 1 MEFI 3 MEFI 2 208 BRN...
Page 675 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Discrete Input Circuit Check(2 of 5) NOTE: The ECM should only be replaced after all switches and circuits have been tested and found to be functioning properly. TESTING BUZZER Step Action PROCEED TO Key ON, Engine OFF. Step 2.
Page 676 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Discrete Input Circuit Check (3 of 5) TESTING GEAR LUBE MONITOR SWITCH Step Action PROCEED TO a. Disconnect BLU/TAN or TAN/WHT wire from gear lube monitor. b. Empty gear lube from monitor. Step 2. Step 3. c.
Page 677 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Discrete Input Circuit Check (4 of 5) TESTING CIRCUITS FOR SHORT-TO-GROUND (–) Step Action PROCEED TO a. Disconnect BLU/TAN or BLU wire from oil pressure switch. b. Disconnect BLU/TAN or TAN/WHT wire from gear lube monitor.
Page 678 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Discrete Input Circuit Check (5 of 5) TESTING FOR OPEN CIRCUITS Step Action PROCEED TO a. Disconnect BLU/TAN or BLU wire from oil pressure switch. b. Disconnect BLU/TAN or TAN/WHT wire from gear lube monitor. c.
Page 679 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Clearing Trouble Codes Clearing Codes Using CodeMate Tester NOTE: When clearing codes without the use of a scan tool, the battery must be fully charged. The ability to clear codes is directly dependent on the battery being fully charged and able to start the engine with adequate cranking rpm.
Page 680 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Diagnostic Testing Code 14 (1 of 3): Engine Coolant Temperature (ECT) Sensor Circuit MEFI 1 MEFI 3 MEFI 2 J1-2 J2-11 J1-29 J2-18 CIRCUIT DESCRIPTION: The Engine Coolant Temperature (ECT) Sensor uses a thermistor to control the signal volt- age to the ECM.
Page 681 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 14 (2 of 3): Engine Coolant Temperature (ECT) Sensor Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? Are you using a Scan Tool? Step 3. Step 8. a.
Page 682 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 14 (3 of 3): Engine Coolant Temperature (ECT) Sensor Circuit Step Action PROCEED TO a. Remove DVOM. b. Ignition ON. c. Connect a test light to battery positive (B+). d. Touch test light to sensor harness terminal “B” CKT 410. Is test light on? Step 13.
Page 683 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 15 (1 of 2): Engine Coolant Temperature (ECT) Sensor Circuit MEFI 2 MEFI 3 J1-2 J2-11 J1-29 J2-18 CIRCUIT DESCRIPTION: The Engine Coolant Temperature (ECT) Sensor uses a thermistor to control the signal volt- age to the ECM.
Page 684 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 15 (2 of 2): Engine Coolant Temperature (ECT) Sensor Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? Are you using a Scan Tool? Step 3. Step 5. Ignition ON.
Page 685 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 21 (1 of 3): Throttle Position (TP) Sensor Circuit MEFI 1 MEFI 3 MEFI 2 J1-13 J2-3 J1-10 J2-26 J1-15 J2-4 CIRCUIT DESCRIPTION: The Throttle Position (TP) Sensor provides a voltage signal that changes as throttle blades open or close.
Page 686 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 21 (2 of 3): Throttle Position (TP) Sensor Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? Are you using a Scan Tool? Step 3. Step 7. a. Throttle closed. b.
Page 687 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 21 (3 of 3): Throttle Position (TP) Sensor Circuit Step Action PROCEED TO a. Ignition OFF. b. Connect a test light to battery positive (B+). c. Touch test light to harness terminal “C” (throttle position sensor signal).
Page 688 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 22 (1 of 3): Throttle Position (TP) Sensor Circuit MEFI 2 MEFI 3 J1-13 J2-3 J1-10 J2-26 J1-15 J2-4 CIRCUIT DESCRIPTION: The Throttle Position (TP) Sensor provides a voltage signal that changes as throttle blades open or close.
Page 689 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 22 (2 of 3): Throttle Position (TP) Sensor Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? Are you using a Scan Tool? Step 3. Step 7. a. Throttle closed. b.
Page 690 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 22 (3 of 3): Throttle Position (TP) Sensor Circuit Step Action PROCEED TO Locate and repair intermittent faulty connections or re- – place faulty throttle position sensor. Locate and repair open or short to ground in CKT 417 or Verify –...
Page 691 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 23 (1 of 3): Intake Air Temperature (IAT) Sensor Circuit MEFI 3 J2-30 J2-3 CIRCUIT DESCRIPTION: The Intake Air Temperature (IAT) Sensor uses a thermistor to control the signal voltage to the ECM. The ECM applies a voltage on CKT 472 to the sensor. When the intake air is cold, the sensor (thermistor) resistance is high, therefore, the ECM will see high signal voltage.
Page 692 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 23 (2 of 3): Intake Air Temperature (IAT) Sensor Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? Are you using a Scan Tool? Step 3. Step 7. Ignition ON Does the scan tool display a temperature less than Step 4.
Page 693 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 25 (1 of 3): Intake Air Temperature (IAT) Sensor Circuit MEFI 3 J2-30 J2-3 CIRCUIT DESCRIPTION: The Intake Air Temperature (IAT) Sensor uses a thermistor to control the signal voltage to the ECM. The ECM applies a voltage on CKT 472 to the sensor. When the intake air is cold, the sensor (thermistor) resistance is high, therefore, the ECM will see high signal voltage.
Page 694 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 25 (2 of 2): Engine Coolant Temperature (IAT) Sensor Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? Are you using a Scan Tool? Step 3. Step 7. Ignition ON.
Page 695 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 33 (1 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit MEFI 1 MEFI 3 MEFI 2 J1-31 J2-19 J1-9 J2-27 J1-29 J2-18 814 BLK CIRCUIT DESCRIPTION: The Manifold Absolute Pressure (MAP) sensor responds to changes in manifold pressure (vacuum).
Page 696 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 33 (2 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? Are you using a Scan Tool? Step 3. Step 7. a.
Page 697 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 33 (3 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit Step Action PROCEED TO a. Switch CodeMate Tester to the “Normal Mode.” b. Ignition OFF. c. Disconnect MAP sensor harness connector. d. Start engine and idle for 2 minutes or until CodeMate Tester indicates a stored trouble code, whichever oc- curs first.
Page 698 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 34 (1 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit MEFI 2 MEFI 3 J1-31 J2-19 MANIFOLD J1-9 J2-27 PRESSURE (VACUUM) J1-29 J2-18 814 BLK CIRCUIT DESCRIPTION: The Manifold Absolute Pressure (MAP) sensor responds to changes in manifold pressure (vacuum).
Page 699 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 34 (2 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? Are you using a Scan Tool? Step 3. Step 7. a.
Page 700 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 34 (3 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit Step Action PROCEED TO a. Remove the jumper wire from CKT416 and 432. b. Connect DVOM from harness terminal “A” CKT 814 to harness terminal “C” CKT 416. Is voltage reading above 4 volts? Step 12.
Page 701 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 41 (1 of 2): Ignition Control (IC) Circuit IC MODULE DISTRIBUTOR MEFI 2 MEFI 3 IGNITION 902 RED COIL J2-23 J1-10 J2-8 J2-10 3 PNK J2-24 J1-24 J2-6 J1-3 121 BRN OR GRY TACH 121 WHT CIRCUIT DESCRIPTION: When the system is running on the ignition module or in crank mode, there is no voltage on...
Page 702 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 41 (2 of 2): Ignition Control (IC) Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? a. Clear trouble code 41. b. Start engine and idle for 2 minutes or until trouble code 41 sets, whichever occurs first.
Page 703 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 42 (1 of 3): Ignition Control (IC) Circuit IC MODULE DISTRIBUTOR MEFI 1 MEFI 3 IGNITION MEFI 2 902 RED COIL J2-23 J1-10 J2-8 J2-10 3 PNK J2-24 J1-24 J2-6 J1-3 121 BRN OR GRY 121 WHT TACH When the system is running on the ignition module or in crank mode, there is no voltage on...
Page 704 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 42 (2 of 2): Ignition Control (IC) Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? a. Clear trouble code 42. b. Start engine and idle for 2 minutes or until trouble code 42 sets, whichever occurs first.
Page 705 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 43 (1 of 3): Knock Sensor (KS) Circuit FUSE 15A TO SYSTEM RELAY MEFI 1 MEFI 3 MEFI 2 KNOCK SENSOR 485 GRN J1-1 MODULE 486 PUR 496 DK BLU J1-30 KNOCK SENSOR CIRCUIT DESCRIPTION: MEFI 1 and MEFI 2 Engine detonation or spark knock is sensed with a module that sends a voltage signal to the ECM.
Page 706 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 43 (2 of 3): Knock Sensor (KS) Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? Do you have a MEFI 3 ECM? Step 7. Step 3. a. Disconnect 5-wire KS module connector b.
Page 707 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 43 (3 of 3): Knock Sensor (KS) Circuit Step Action PROCEED TO Replace faulty KS module. – Replace faulty KS. Verify Repair Trouble code 43 is intermittent. Refer To “Diagnostic – Aids” on facing page. Index Page 5G-80 90-861327--1 OCTOBER 1999...
Page 708 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 44 (1 of 3): Knock Sensor (KS) Circuit FUSE 15A TO SYSTEM RELAY MEFI 2 MEFI 3 KNOCK SENSOR 485 GRN J1-1 MODULE 486 PUR 496 DK BLU J1-30 KNOCK SENSOR CIRCUIT DESCRIPTION: MEFI 1 and MEFI 2 Engine detonation or spark knock is sensed with a module that sends a voltage signal to the ECM.
Page 709 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 44 (2 of 3): Knock Sensor (KS) Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? Do you have a MEFI 3 ECM? Step 7. Step 3. a. Disconnect 5-wire KS module connector b.
Page 710 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 44 (3 of 3): Knock Sensor (KS) Circuit Step Action PROCEED TO Replace faulty KS module. Replace faulty KS. Verify – Repair Trouble code 44 is intermittent. Refer To “Diagnostic Aids” on facing page. Index 90-861327--1 OCTOBER 1999 Page 5G-83...
Page 711 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 45 (1 of 2): Ignition Coil Driver Fault MEFI 3 J1-2 902 RED 121 WHT 121 WHT – IGNITION COIL TO IGN TEMP SENDER 121 WHT J2-20 208 BRN J2-8 585 TAN/WHT 901 TAN J1-26 29 DK GRN 3 PNK...
Page 712 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 45 (2 of 2): Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? a. Ignition ON, engine OFF. b. Using DVOM, measure voltage at coil positive (+) termi- Step 3. Step 7.
Page 713 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 51 (1 of 1): Calibration Memory Failure 72801 CIRCUIT DESCRIPTION: This test allows the ECM to check for a calibration failure by comparing the calibration value to a known value stored in the EEPROM. This test is also used as a security measure to prevent improper use of calibrations or changes to these calibrations that may alter the designed function of EFI.
Page 714 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 52 (1 of 1): EEPROM Failure 72801 CIRCUIT DESCRIPTION: This test allows the ECM to check for a calibration failure by comparing the calibration value to a known value stored in the EEPROM. This test is also used as a security measure to prevent improper use of calibrations or changes to these calibrations that may alter the designed function of EFI.
Page 715 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 61 (1 of 2) Fuel Pressure (FP) Circuit MEFI 3 416 GRY J2-3 475 GRN J2-26 J2-4 813 BLK CIRCUIT DESCRIPTION: The fuel pressure (FP) Sensor provides a voltage signal that changes with measured fuel pressure.
Page 716 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 61 (2 of 3) Fuel Pressure (FP) Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? Are you using a Scan Tool? Step 3. Step 7. a. Ignition ON. Does scan tool indicate fuel pressure sensor voltage Step 6.
Page 717 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 61 (3 of 3) Fuel Pressure (FP) Circuit Step Action PROCEED TO a. Ignition OFF. b. Connect a test light to battery positive (B+). c. Touch test light to harness terminal “C” (fuel pressure sensor signal).
Page 718 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 62 (1 of 3) Fuel Pressure (FP) Sensor Circuit MEFI 3 416 GRY J2-3 475 GRN J2-26 J2-4 813 BLK CIRCUIT DESCRIPTION: The fuel pressure (FP) Sensor provides a voltage signal that changes with measured fuel pressure.
Page 719 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 62 (2 of 3) Fuel Pressure (FP) Sensor Circuit Step Action PROCEED TO Was the “On-Board Diagnostic” (OBD) System Check Step 2. Performed? Are you using a Scan Tool? Step 3. Step 7. a. Ignition OFF. Does scan tool indicate fuel pressure sensor voltage Step 4.
Page 720 DIAGNOSTICS SERVICE MANUAL NUMBER 24 Code 62 (3 of 3) Fuel Pressure (FP) Sensor Circuit Step Action PROCEED TO Locate and repair intermittent faulty connections or re- – place faulty fuel pressure sensor. Locate and repair open or short to ground in CKT 475 or Verify –...
Page 721 DIAGNOSTICS SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 5G-94 90-861327--1 OCTOBER 1999...
Page 722 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 COOLING SYSTEM Section 6A - Seawater Cooled Models Table of Contents Torque Specifications ....6A-2 Seawater Pump Bearing Housing .
Page 723 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Torque Specifications Description lb-in. lb-ft Alternator Mounting Bracket Power Steering Pump Bracket Seawater Pump Brace Seawater Pump Bracket To Block Seawater Pump Cover Thermostat Cover Thermostat Housing Thru-Hull Pickup Nut Alternator To Mounting Bracket Water Circulating Pump Seawater Pump Clamping Screw On Casting Bracket Water Temperature Sender...
Page 724 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Lubricants / Sealants / Adhesives Description Part Number Quicksilver Loctite 27131 92-809820 Quicksilver Perfect Seal 92-34227--1 Quicksilver 2-4-C Marine Lubricant With Teflon 92-825407A3 Quicksilver High Performance Gear Lube 92-816026A2 Quicksilver Liquid Neoprene 92-25711--3 Quicksilver Special Lubricant 101 92-13872A1 Silicone Sealant Or Equivalent...
Page 725 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Seacock (Seawater Inlet Valve) If a seacock is being used, it must be installed between water pickup and seawater pickup pump (or sea strainer), to allow operator to shut off the seawater in case of a leak or when boat is not in use.
Page 726 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Seawater Pickups NOTICE Refer to manufacturer’s instructions for information on removal and installation of other than Quicksilver Seawater Pickups. IMPORTANT: Seal the inside edges of any hole made through the hull with a suitable sealant to prevent water absorption and deterioration.
Page 727 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Transom Mounted 72640 Hose Fitting Nut (4) Gasket - Between Pickup and Transom O-Ring (4) Washer (4) Screw (4) Plastic Pug Pickup Screen Screw (2) 1. Seal the inside edges of the 1-1/2 in. (38 mm) hole hose fitting. 2.
Page 728 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Quicksilver Sea Strainer NOTICE Refer to manufacturer’s instructions for information on other than Quicksilver Sea Strainer. Removal CAUTION If boat is in water while working on seawater strainer, close seacock, if so equipped. If boat is not equipped with a seacock, remove and plug seawater inlet hose to pre- vent a siphoning action that may occur, allowing seawater to flow from the drain holes or removed hoses and enter boat.
Page 729 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Cleaning and Inspection 1. Remove and clean filter element. 2. Remove drain plug 72673 Quicksilver Seawater Strainer Shown Screws and Washers Cover Glass O-Ring Strainer Housing Drain Plug and Sealing Washer Gasket 3. Flush components with clean water. Installation IMPORTANT: Mount seawater strainer in a vibration-free location.
Page 730 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 2. Remove plug from seawater inlet hose (if installed previously) and install hose on strainer. Install seawater outlet hose. Use two hose clamps on each hose connection. Tighten clamps securely. 72645 Seawater Inlet Hose Seawater Outlet Hose Double Hose Clamps 3.
Page 731 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Seawater Pickup Pump Output Test If an overheating problem exists, use this test to determine if a sufficient amount of water is being supplied to cool the engine. IMPORTANT: The following information should be observed before proceeding with test: •...
Page 732 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 2. Models With Sterndrive (Alpha) Mounted Seawater Pump - remove water inlet hose, which runs between gimbal housing water tube and engine, and replace with another hose of same diameter, but approximately 3 ft. (1 m) longer. Hose should be of adequate wall thickness to prevent it from kinking when performing test.
Page 733 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Disassembly 1. Remove the five screws from the seawater pump body. 75277 Screws (5) Seawater Pump Body 2. Remove seawater pump body and wear plate from bearing housing. 75275 Seawater Pump Body Wear Plate Bearing Housing 3.
Page 734 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Reassembly 1. Lubricate seawater pump impeller with a water and soap solution. Install impeller into housing by rotating and pushing it into place. Push it down until flush with housing. 71118 71150 Impeller 2.
Page 735 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Seawater Pump Bearing Housing Disassembly 1. Remove gasket, inner wear plate and quad ring seal. Discard gasket and quad ring seal. 72656 72655 Quad Ring Seal 2. Press hub off shaft with Universal Puller Plate and an arbor press. 72648 Universal Puller Plate (91-37241) 3.
Page 736 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 4. Remove snap ring from bearing housing bore and press shaft and bearings out pulley end of housing. Bearings have a slip fit in housing; do not use excessive force. 72658 72657 Snap Ring 5.
Page 737 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Reassembly 1. Apply a thin coat of Loctite 27131 to outside diameter of two new bearing housing rear seals; then install seals in housing with seal lips facing impeller end. Press first seal in until it bottoms out and second seal in until flush with housing.
Page 738 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 4. Pack bearings and cavity between bearings with Shell Alvania No. 2 Grease or substi- tute. Slide bearings and shaft into bearing housing bore and install snap ring. 72661 Shaft With Bearings 72658 Snap Ring 5.
Page 739 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 6. Apply Quicksilver Special Lubricant 101 to pump shaft. Using an arbor press and appro- priate tool, press pulley hub onto pump shaft to dimension shown. 72664 .260 Inch (6.6 mm) IMPORTANT: Pulley hub must be pressed onto shaft to exact dimension on pumps with stamped steel mounting bracket as this establishes proper drive belt alignment.
Page 740: Water Circulating Pump
SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Water Circulating Pump Removal 1. Drain water from cylinder block. 2. Break loose circulating pump pulley attaching bolts. Do not remove bolts at this time. 3. Loosen alternator tensioner pulley, then pivot alternator inward and remove the serpen- tine drive belt.
Page 741 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Drive Belt Tension Adjustment NOTICE Refer to SECTION 4B - “Ignition System” Flushing Seawater Cooling System NOTICE Refer to SECTION 1B - “Maintenance” Thermostat Removal 1. Drain water from cylinder block and exhaust manifolds. 2.
Page 742 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Testing 1. Clean thermostat in soap and water to remove any deposits or debris. 2. Inspect thermostat for corrosion or other visible damage. 3. If thermostat is suspected of producing insufficient engine temperature, check thermo- stat for leakage by holding it up to a lighted background.
Page 743 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 IMPORTANT: When performing procedures d. - f. water must be agitated thoroughly to obtain accurate results. d. Plug in tester and observe temperature at which thermostat opens (thermostat drops off thread). Thermostat must open at specified temperature stamped on ther- mostat.
Page 744 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Auxiliary Hot Water Heater Installation IMPORTANT: When connecting a cabin heater or hot water heater, certain require- ments must be met: • Supply hose (from engine to heater) and return hose (from heater to engine) MUST NOT EXCEED 5/8 in.
Page 745 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Water Tap Locations For Propshaft Coolers IMPORTANT: Tapping into the wrong location can cause the engine to vapor lock or run too cold. MIE (Inboard) Models Only: Splice into the port-side exhaust manifold water hose. This provides the temperatures and pressures required to cool the packing glands without damaging them.
Page 746 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 Water Flow Diagrams 305 cid and 350 cid Bravo, Inboard and Ski Engines NOTE: Certain components in the following diagram may look different than on your particu- lar power package, but the water flow paths remain similar on all engines. 75149 Seawater Intake (From Sterndrive) Seawater Pump...
Page 747 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 305 cid and 350 cid Alpha Engines NOTE: Certain components in the following diagram may look different than on your particu- lar power package, but the water flow paths remain similar on all engines. 75125 Seawater Intake (From Sterndrive) Power Steering Cooler...
Page 748 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index 90-861327--1 OCTOBER 1999 Page 6A-27...
Page 749 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 6A-28 90-861327--1 OCTOBER 1999...
Page 750 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 COOLING SYSTEM Section 6B - Closed Cooled Models Table of Contents Torque Specifications ....6B-2 Thermostat ......6B-10 Lubricants / Sealants / Adhesives .
Page 751: Coolant Specification
CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Torque Specifications Description lb-in. lb-ft Heat Exchanger End Cap 36-72 Thermostat Cover Heat Exchanger Mounting Brackets Hose Clamps Securely Drain Plugs Lubricants / Sealants / Adhesives Description Part Number Quicksilver 2-4-C Marine Lubricant With Teflon 92-825407A3 Quicksilver Perfect Seal 92-34227--1...
Page 752: Coolant Recommendations
CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Description The cooling system is composed of two separate subsystems: the seawater system and the closed cooling system. The seawater system is similar in function to the fan used in an auto- mobile because it absorbs heat from the closed cooling system as it passes through the heat exchanger.
Page 753: Pressure Cap Maintenance
CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Before starting engine each day, ensure that coolant is visible in coolant recovery bottle. If coolant is not visible, check fresh water section of cooling system (including coolant recov- ery system) for leaks and repair. Refill fresh water section with recommended coolant solu- tion as outlined under “Changing Coolant,”...
Page 754: Heat Exchanger Repair
CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 5. Check condition of locking tabs on cap. Replace cap if tabs are bent or cracked. 6. Check gasket for cracks or other damage. IMPORTANT: Cap MUST be replaced if damaged. 72714 Rubber Seal Gasket Locking Tabs (1 Hidden) 7.
Page 755: Testing Coolant For Alkalinity
CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Testing Closed Cooling System Testing Coolant for Alkalinity WARNING Allow engine to cool before removing pressure cap as sudden loss of pressure could cause hot coolant to boil and discharge violently. After engine has cooled, turn cap 1/4 turn to allow any pressure to escape slowly, then push down and turn cap all the way off.
Page 756: Testing For Cylinder Head Gasket Leak
CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 9. If no leakage could be found in above steps, engine is leaking internally. Leaking may be caused by one or more of the following: (1) loose cylinder head bolts or damaged gasket, (2) loose intake manifold bolts or damaged gasket, (3) loose exhaust elbow or distribution block retaining nuts or damaged gasket, (4) cracked or porous cylinder head or block, or (5) cracked or porous exhaust manifold.
Page 757: Testing Heat Exchanger
CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Do not confuse normal warm-up expansion with a failed head gasket. Normal warm-up produces an intermittent flow of coolant that will stop within approximately five minutes at a given rpm. A head gasket leak will not stop because the one thing that marks a failed head gasket is the continued passage of air.
Page 758 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 IMPORTANT: Cap MUST be replaced if damaged. 72714 Rubber Seal Gasket 5. Using a cooling system pressure tester (similar to one shown), test cap to be sure that it releases at proper pressure and does not leak. (Refer to instructions which accompany tester for correct test procedure.) Cap must relieve pressure at 16 psi (110 kPa), and must hold rated pressure for 30 seconds without going below 11 psi.
Page 759 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Thermostat Removal NOTE: If coolant flow is restricted or fails to occur, a wire should be repeatedly inserted into all drain holes to ensure there are no obstructions in passages. Remove fitting, if necessary, to insert wire completely into drain hole.
Page 760 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Testing 1. Clean thermostat in soap and water to remove any deposits or debris. 2. Inspect thermostat for corrosion or other visible damage. 75747 3. If thermostat is suspected of producing insufficient engine temperature, check thermo- stat for leakage by holding it up to lighted background.
Page 761 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Installation CAUTION Avoid seawater pickup pump impeller damage. DO NOT operate engine without cooling water being supplied to seawater pickup pump. 1. Remove thermostat housing and gaskets. Discard gaskets. 2. Clean gasket surfaces on thermostat cover, thermostat housing and intake manifold. 3.
Page 762: Changing Coolant
CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Changing Coolant NOTICE For information and procedures on draining the seawater cooling system of Seawater Cooled (Raw–water) Models, refer to SECTION 6A. For information and procedures on draining the Seawater Section of Closed Cooling (Coolant) Models refer to SECTION 1B.
Page 763: Cleaning System
CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 3. After coolant has drained completely, reinstall petcocks and hoses. Tighten clamps and petcocks securely. 4. Remove coolant recovery bottle from mounting bracket and pour out coolant. 5. Clean system as outlined in “Cleaning System.” 6.
Page 764 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 4. Clean gasket material from end plates and heat exchanger. 71515 Heat Exchanger Sealing Washer End Cap Gasket 5. Clean water passages in heat exchanger by inserting a suitable size wire brush into each passage.
Page 765: Filling Closed Cooling Section
CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Filling Closed Cooling Section CAUTION Alcohol or Methanol base antifreeze or plain water are not recommended for use in coolant section of Closed Cooling System at any time. It is recommended that coolant section of Closed Cooling System be filled with a 50/50 mix- ture of Extended Life Coolant and pure, soft water.
Page 766 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 3. Add coolant solution to heat exchanger, as required, to maintain coolant level at filler neck. 4. After engine has reached normal operating temperature thermostat is fully open and coolant level remains constant, fill heat exchanger until coolant level is into filler neck and begins to flow into coolant recovery bottle plastic tubing.
Page 767 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 CAUTION On closed cooling models, the heater must be mounted lower than the fill cap on the heat exchanger. If the heater is higher than the fill cap on the heat exchanger and some coolant is lost from system, an air pocket may form in the closed cooling system.
Page 768 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Heat Exchanger Bracket Hardware 75598 74745 75213 74988 Typical Engine Shown Gasket Heat Exchanger Bracket and Pads Thermostat Housing Screws, Stainless Steel Bleeder Valve Thermostat Quad-Ring Seal Outer Diameter of Thermostat Thermostat Cover Screws with Lockwashers Engine Temperature Gauge Sender ECT Sender...
Page 769 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Heat Exchanger Hose Connections 74073 75230 74073 75209 75212 Typical Engine Shown Heat Exchanger Large Hose Clamps Starboard Heat Exchanger-to-Exhaust Manifold Hose Water Circulating Pump Hose Port Heat Exchanger-to-Exhaust Manifold Hose (MIE) Port Heat Exchanger-to-Exhaust Manifold Hose (MCM) Cool Fuel System (or Seawater Pipe, if so equipped)-to-Heat Exchanger Hose Coolant Identification Decal Fuel Lines Aligned to Avoid Starboard Water Hose...
Page 770 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Closed Cooling System Water Flow Diagram MCM / MIE Models 75005 Seawater Inlet Hose Seawater Pump Transmission Fluid Cooler, or Power Steering Cooler Fuel Cooler Heat Exchanger, Typical Thermostat Housing and Cover Assembly Engine Water Circulating Pump Engine Block and Cylinder Head Assembly Exhaust Manifold, Typical...
Page 771 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 Draining Diagram (Coolant Section of System) 75005 Remove Hoses (Lift, Lower or Bend To Completely Drain). Remove Block Plugs (Repeatedly Clean Out Holes Using A Stiff Wire Until Entire System Is Drained). Index Page 6B-22 90-861327--1 OCTOBER 1999...
Page 772 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index 90-861327--1 OCTOBER 1999 Page 6B-23...
Page 773 CLOSED COOLED MODELS SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 6B-24 90-861327--1 OCTOBER 1999...
Page 774: Mcm (Sterndrive) Engines With Thru-Transom Exhaust
GENERAL SERVICE MANUAL NUMBER 24 EXHAUST SYSTEM Section 7A - General Table of Contents Exhaust System Requirements ..7A-2 Exhaust Elbow Risers ... . 7A-2 MCM (Sterndrive) Engines With Thru-Transom Exhaust...
Page 775 Damage caused by water in the engine will not be covered by MerCruiser Limited Warranty, unless this damage is the result of defective part(s). Exhaust Elbow Risers On all engines to determine if exhaust elbow risers are required, take measurements (a) and (b), with boat at rest in the water and maximum load aboard.
Page 776: Mie (Inboard) Engines
GENERAL SERVICE MANUAL NUMBER 24 MIE (Inboard) Engines When designing and installing exhaust system, it is very important that the following addi- tional points be taken into consideration: 1. System layout and construction must prevent cooling system discharge water from flow- ing back into engine and also must prevent seawater from entering engine via exhaust at any point.
Page 777: Exhaust Tube Requirements
GENERAL SERVICE MANUAL NUMBER 24 Exhaust Tube Requirements IMPORTANT: When installing through-transom exhaust, it is recommended that the exhaust bellows on the transom assembly be removed. This is necessary to avoid creating a vacuum at the exhaust outlet in the propeller at higher boat speeds. This vacuum could degrade propeller performance on some boats.
Page 778 GENERAL SERVICE MANUAL NUMBER 24 e. Tighten clamp. Torque to 35 lb-in. (4 Nm). 22184 22184 Exhaust Tube Clamp SIDE Marking Exhaust Tube Grounding Clip Index 90-861327--1 OCTOBER 1999 Page 7A-5...
Page 779 GENERAL SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 7A-6 90-861327--1 OCTOBER 1999...
Page 780 MANIFOLDS, ELBOWS AND RISERS SERVICE MANUAL NUMBER 24 EXHAUST SYSTEM Section 7B - Manifolds, Elbows And Risers Table of Contents Torque Specifications ....7B-2 Installation .
Page 781: Torque Specifications
MANIFOLDS, ELBOWS AND RISERS SERVICE MANUAL NUMBER 24 Torque Specifications Fastener Location lb-in. lb-ft Hose Clamp Securely Exhaust Elbow or Risers to Manifold Exhaust Manifold to Cylinder Head Lubricants / Sealants / Adhesives Description Part Number Quicksilver Perfect Seal 92-34227--1 Quicksilver Loctite 510 Sealant 92-804874 Disassembly...
Page 782 MANIFOLDS, ELBOWS AND RISERS SERVICE MANUAL NUMBER 24 6. Remove exhaust manifold fasteners. Remove manifold assembly and discard gaskets. 75749 Exhaust Elbow Restrictor Gasket Open Gasket (Later Models and Service) Exhaust Manifold Bolts Cleaning and Inspection 1. Clean gasket material from all surfaces and wash parts in solvent. 2.
Page 783 MANIFOLDS, ELBOWS AND RISERS SERVICE MANUAL NUMBER 24 8. Look at the condition of the metal around the exhaust outlet in the casting. Inspect for damaged metal caused by salt water or exhaust gas corrosion in the manifold, elbow and riser, if equipped. Replace all damaged parts. 76341 Inspect Area Around Exhaust Outlet 9.
Page 784: Installation
MANIFOLDS, ELBOWS AND RISERS SERVICE MANUAL NUMBER 24 Installation Gaskets NOTE: The service replacement gasket may not be the same type of gasket that was used in production. The fire ring gasket with 4 slots is used between all manifolds, risers and exhaust elbows. IMPORTANT: After applying Loctite 510 to the gasket, assemble components im- mediately.
Page 785: Manifold
MANIFOLDS, ELBOWS AND RISERS SERVICE MANUAL NUMBER 24 Manifold 1. Using new gasket, install exhaust manifold to cylinder head. Torque fasteners to 25 lb-ft (34Nm). 2. Using a new gasket, install exhaust elbow to exhaust manifold. Torque fasteners to 25 lb-ft (34Nm).
Page 786 MANIFOLDS, ELBOWS AND RISERS SERVICE MANUAL NUMBER 24 4. Starboard Manifold: a. Install bolt to secure water separating fuel filter bracket to exhaust manifold. b. Install shift plate assembly on exhaust elbow (MCM only). c. Connect instrument harness plug to engine harness, if disconnected previously. d.
Page 787 MANIFOLDS, ELBOWS AND RISERS SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 7B-8 90-861327--1 OCTOBER 1999...
Page 788 COLLECTORS SERVICE MANUAL NUMBER 24 EXHAUST SYSTEM Section 7C - Collectors Table of Contents Torque Specifications ....7C-2 Silent Choice Exhaust System ..7C-8 Lubricants / Sealants / Adhesives .
Page 789 COLLECTORS SERVICE MANUAL NUMBER 23 Torque Specifications Fastener Location lb-in. lb-ft Block-Off Plate Exhaust Pipe to Gimbal Housing Exhaust Pipe to T-Pipe 20-25 27-34 T-Pipe to Gimbal Housing Upper Exhaust Pipe to Lower Exhaust Pipe Exhaust Elbow Air Pump Mount Muffler End Plate Mode Switch Securely...
Page 790: Bullhorn Exhaust
COLLECTORS SERVICE MANUAL NUMBER 24 Bullhorn Exhaust Shutter Replacement IMPORTANT: Engine does not have to be removed to change shutters. 1. Loosen clamps and remove exhaust pipe, elbow and exhaust hose. 2. Replace water shutter. 3. Reinstall pipe, elbow and hose. Tighten clamps securely. 75760 Exhaust Flapper Rubber Grommets...
Page 791: Component Replacement
COLLECTORS SERVICE MANUAL NUMBER 23 Component Replacement To replace any components in exhaust system, the following must be adhered to: • All mating surfaces must be clean. • O-ring must remain in groove to properly seal joints to prevent leakage. •...
Page 792: Thru-Transom Exhaust
COLLECTORS SERVICE MANUAL NUMBER 24 Thru-Transom Exhaust Shutter Replacement IMPORTANT: A block off plate must be installed when using thru-transom exhaust or below swim platform kits. 22057 Block Off Plate Bolts (4) 1. Remove exhaust hose clamps, then hose. 2. Chisel rivets away from both support members. 27761 Shutter Hinge Water Shutter - Opens Toward Outside Of Boat...
Page 793: Component Replacement
COLLECTORS SERVICE MANUAL NUMBER 23 Component Replacement 72740 Transom Exhaust Kit Screw And Nut (4) Support Member Water Shutter (Hinge Must Be Vertical) Gasket Exhaust Flange Bolts, Washers and Nuts (3) Clamp Cover (Flapper) Index Page 7C-6 90-861327--1 OCTOBER 1999...
Page 794 COLLECTORS SERVICE MANUAL NUMBER 24 Below Swim Platform Exhaust Pipe This exhaust kit may be used on any MerCruiser installation having a 4 in. (102 mm) exhaust elbow. 72742 8 Per Kit 2 Per Kit The below swim platform exhaust pipe can be modified for specific height applications by cutting pipe at location shown.
Page 795 Damage caused by water in the engine will not be covered by Mercury MerCruiser Warranty, unless this damage is the result of defective part(s). Exhaust Tube Installation 1.
Page 796 COLLECTORS SERVICE MANUAL NUMBER 24 (1.) Position tube so that SIDE markings on tube are facing toward the right and left sides. (2.) Install clamp. (3.) Tighten clamp securely. 22184 22184 Exhaust Tube Clamp Side Marking Exhaust Tube Grounding Clip 72539 Silencer Valve Assembly Hose Clamps...
Page 797 COLLECTORS SERVICE MANUAL NUMBER 23 Air Tube Routing 1. Route air tubing from air pump to silencer valve cylinders. Do not route air tubing close to hot surfaces. Excessive heat will damage air tubes. 72775 Single Engine Air Tube T-Fittings Air Pump Assembly Air Tube To Air Cylinder - On Each Silencer Valve 72776...
Page 798 COLLECTORS SERVICE MANUAL NUMBER 24 Maintenance 1. Air Intake Filter (32-17272) must be checked once each year. If filter is clogged or partially clogged, replace. The filter pad is glued in and may be removed with needle-nose pliers. Clean surface in casting, apply a single dot of Quicksilver Sound Blanket Glue to center of casting, and install new filter.
Page 799 Damage caused by water in the engine will not be covered by Mercury MerCruiser Warranty, unless this damage is the result of defective part(s). IMPORTANT: Restrictor gaskets (if equipped) must be installed in order shown.
Page 800 COLLECTORS SERVICE MANUAL NUMBER 24 Cleaning and Inspection 1. Disassemble muffler as shown. 72782 Removable End Plate 4 Screws Secure End Plate O-Ring Seal Element - When Reassembling, Seat Tab In Slot In Casting 2. Clean (using pressurized water) and inspect parts, including filter element and O-ring seal.
Page 801 COLLECTORS SERVICE MANUAL NUMBER 23 Installation 1. Install muffler, as shown, into exhaust hose and molded tube. Fabricate muffler to tran- som using 4-in. I.D. exhaust hose, cut to required length. NOTE: Removable end of muffler ALWAYS goes toward exhaust elbow. This places direc- tion marks on muffler body casting at the upper rear corner on the port side.
Page 802: Maintenance Instructions
COLLECTORS SERVICE MANUAL NUMBER 24 Maintenance Instructions Maintenance inspection is owner’s responsibility and must be performed at intervals speci- fied in owner’s Operation and Maintenance Manual. 1. Check exhaust elbow attaching nuts for adequate tightness [20-25 lb-ft (27-34 Nm)]. 2. Check hose clamps for adequate tightness. 3.
Page 803 COLLECTORS SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 7C-16 90-861327--1 OCTOBER 1999...
Page 804 VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 DRIVES Section 8A - Velvet Drive In-Line And V-Drive Transmission Table of Contents Specifications ..... . . 8A-2 Shift Cable Adjustment .
Page 805: Specifications
VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 Specifications Identification The transmission identification plate is located on the top left side of the transmission. Refer to charts following to determine engine and transmission combinations. 72839 Transmission Identification Plate Model Number Ratio (In Forward Gear) Serial Number...
Page 806: Fluid Specifications
VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 Fluid Specifications Make and Model Capacity Fluid Type Mobil 424 or Velvet Drive Dexron III Automatic Transmission Fluid 71C In-Line 1-1/2 (1.33) Do Not Mix! Velvet Drive Mobil 424 or 72 Series Dexron III Automatic Transmission Fluid 3 (2.75)
Page 807 VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 Important Information Shift Control and Cables CAUTION Shift control and shift cable must position transmission shift lever exactly as stated in this manual, or transmission, as a result of improper shift lever positioning, will not be covered by Velvet Drive Warranty.
Page 808 VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 7. Always use specified oil cooler, hoses and fittings. Hoses must be at least 13/32 in. (10.5 mm) I.D. Oil cooler, hoses and fittings must be sufficient size to maintain transmission fluid (in sump) at 140-190°F (60-88°C).
Page 809 VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 Checking Transmission Fluid Level IMPORTANT: Use only specified transmission fluid. Refer to “Specifications.” IMPORTANT: To accurately check fluid level, engine must be run at 1500 rpm for 2 minutes immediately prior to checking level. 72526 Dipstick Full Mark...
Page 810: Draining Transmission
VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 Changing Transmission Fluid Draining Transmission 1. Clean area around cooler hose shown and proceed as follows: a. Disconnect hose from elbow fitting. b. Remove elbow fitting from bushing. c. Drain oil from transmission, cooler and cooler hoses into a suitable container. 72840 Transmission With 1:1 Ratio Hose...
Page 811 VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 71305 V-Drive Transmission Hose Elbow Fitting Bushing 2. Remove bushing, spring and strainer tube from transmission case. Allow transmission to drain completely. 3. Clean strainer tube in suitable solvent. 71307 Bushing Spring Plastic Strainer Tube...
Page 812: Filling Transmission
VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 5. Install plastic strainer tube with the notch DOWN and OUT toward the side of the case. 71306 Plastic Strainer Tube Notch 6. Install spring. 7. Coat bushing threads with Quicksilver Perfect Seal. Install and torque bushing to 25 lb-ft (34 Nm).
Page 813: Removal
VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 Removal NOTICE The following procedure describes removal of transmission without removing engine. If engine must be removed, refer to SECTION 2 (see “Table of Contents”). 1. Drain transmission fluid. 2. Disconnect fluid cooler hoses. 3.
Page 814 VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 11. Connect and adjust shift cable(s) as outlined in SECTION 2C, “MIE Models - Velvet Drive Transmissions”. IMPORTANT: Velvet Drive Transmission Warranty is jeopardized if the shift lever pop- pet ball or spring is permanently removed, if the shift lever is repositioned or changed in any manner, or if remote control and shift cable do not position shift lever exactly as shown.
Page 815: Shift Lever Installation
VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 Shift Lever Installation IMPORTANT: Velvet Drive Warranty is jeopardized if the shift lever poppet spring and/ or ball is permanently removed, or if the shift lever is changed, repositioned or if the linkage between the remote control and the transmission shift lever does not have sufficient travel in both directions.
Page 816: Pressure Test
VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 Pressure Test 1. Install pressure gauge. 72845 Main Line Pressure Tap - Remove Temperature Switch 2. With boat in water, start engine and run until normal operating temperature is reached. 3.
Page 817 VELVET DRIVE IN-LINE AND V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 24 THIS PAGE IS INTENTIONALLY BLANK Index Page 8A-14 90-861327--1 OCTOBER 1999...
Page 818 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 DRIVES Section 8B - Velvet Drive 5000 Series Transmission Table of Contents Velvet Drive 5000A Down Angle Important Information ....8B-6 Specifications .
Page 819 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 Velvet Drive 5000A Down Angle Specifications Identification The transmission identification plate is located on the top left side of the transmission. Refer to charts following to determine engine and transmission combinations. 73247 Transmission Identification Plate Model Number...
Page 820 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 Transmission Pressure Specifications Neutral Gear psi (kPa) Forward Gear or Reverse Gear psi (kPa) Engine rpm Engine rpm Min. Max. Min. Max. 10 (69) 50 (344) 200 (1379) 400 (2757) 2400 50 (344) 70 (483) Torque Specifications...
Page 821 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 Velvet Drive 5000V V-Drive Specifications Identification The transmission identification plate is located on the top left side of the transmission. Refer to charts following to determine engine and transmission combinations. 72839 Transmission Identification Plate Model Number Ratio (In Forward Gear)
Page 822 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 Transmission Pressure Specifications Neutral Gear psi (kPa) Forward Gear psi Reverse Gear psi Engine (kPa) (kPa) MIn. Max. Min. Max. Min. Max. – – 70 (483) – 70 (483) – 115 (793) 135 (931) 115 (793) 140 (965)
Page 823 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 Important Information Engine Engine rotation is indicated on engine specifications and serial number decal on the engine. Engine rotation is described when observed from the rear of the engine (transmission end) looking forward (water pump end).
Page 824 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 Transmission / Propeller Rotation These transmissions are full power reversing transmissions, allowing a standard (LH rota- tion) engine to be used for both propeller rotations. Propeller rotation (output shaft rotation) is determined by shift cable attachment at the remote control. Be sure to use correct rotation propeller and shift cable hook up for direction desired.
Page 825 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 For Left-Hand Propeller Shaft Rotation: Shift cable hookup at remote control must result in shift cable end guide moving in direction “A” when remote control handle is placed in for- ward position. For Right-Hand Propeller Shaft Rotation: Shift cable hookup at remote control must result in shift cable end guide moving in direction “B”...
Page 826 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 IMPORTANT: Velvet Drive Transmission Warranty is jeopardized if the shift lever pop- pet ball or spring is permanently removed, if the shift lever is repositioned or changed in any manner, or if remote control and shift cable do not position shift lever exactly as shown.
Page 827 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 Transmission Shift Lever and Shift Cable Bracket 1. The lever has three holes as illustrated following. For use with Quicksilver shift cables, the anchor stud is located in the middle hole. 73249 Shift Lever Shift Cable Anchor Stud Location (For Quicksilver Shift Cables)
Page 828 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 Shift Cable Adjustment IMPORTANT: Velvet Drive Transmission Warranty is jeopardized if the shift lever pop- pet ball or spring is permanently removed, if the shift lever is repositioned or changed in any manner or if remote control and shift cable do not position shift lever exactly as shown.
Page 829 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 IMPORTANT: The Velvet Drive 5000 Series transmissions are full reversing transmis- sion. Direction of output/propeller rotation is determined by hookup of shift cable at remote control. 73291 Position Is Forward Gear For LH Rotation Propeller Input Output Output Shaft...
Page 830 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 IMPORTANT: Be certain anchor stud is installed in the front hole as shown in the illus- tration following. 73284 Anchor Stud In Front Hole Shift Cable Bracket Remote control must provide a total shift cable travel (at transmission end) of at least 2-3/4 in.
Page 831 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 1. Place remote control shift lever and transmission shift lever in neutral position. 2. Remove nuts and washers from shift cable attaching studs. 3. Locate center of remote control and control shift cable play (backlash) as follows: a.
Page 832 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 CAUTION Remote control and shift cable must position transmission shift lever exactly as shown, or transmission failure may occur. Do not remove poppet ball or spring. 73248 Transmission Shift Lever Poppet Ball Must Be Centered in This Detent Hole when Left-Hand Propeller Shaft Rotation Is Desired Poppet Ball Must Be Centered in This Detent Hole when Right-Hand Propeller Shaft Rotation Is Desired...
Page 833 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 10. Install nut and washer to cable barrel stud. Tighten until they contact. Tighten securely, but DO NOT OVERTIGHTEN. 71972 71780 Typical Single Cable Installation - Rear Approach Cable End Guide Spacer (As Required) Elastic Stop Nut And Washer Bushing(s)
Page 834 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 Checking Transmission Fluid Level IMPORTANT: Use only specified transmission fluid. Refer to “Specifications.” Check transmission fluid before running engine each day, as follows: 1. Remove dipstick. Check fluid level as indicated on dipstick. Fluid level may be some- what over full mark, as some of the fluid from transmission fluid cooler and hoses may have drained back into transmission.
Page 835 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 Changing Transmission Fluid Draining Transmission 1. Clean area around drain plug shown. 2. Remove dipstick and then remove drain plug. Drain oil from transmission into a suitable container. 73252 Drain Plug 3.
Page 836 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 Filling Transmission IMPORTANT: Use only specified transmission fluid. Refer to “Specifications.” 1. Remove dipstick. Fill transmission with fluid, through dipstick hole, to bring up to full mark. 73250 Dipstick Full Mark Dipstick Tube IMPORTANT: To accurately check fluid level, run engine at 1500 rpm for 2 minutes immediately prior to checking level.
Page 837 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 9. Support rear part of engine using a suitable hoist or wooden blocks under flywheel hous- ing. 10. Support transmission with hoist or by other suitable means through the lifting eye on the transmission case.
Page 838 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 8. Connect and adjust shift cable(s). IMPORTANT: Velvet Drive Transmission Warranty is jeopardized if the shift lever pop- pet ball or spring is permanently removed, if the shift lever is repositioned or changed in any manner, or if remote control and shift cable do not position shift lever exactly as shown.
Page 839 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 Shift Lever Installation IMPORTANT: Velvet Drive Warranty is jeopardized if the shift lever poppet spring and/ or ball is permanently removed, or if the shift lever is changed in any manner, or repo- sitioned, or if the linkage between the remote control and the transmission shift lever does not have sufficient travel in both directions.
Page 840 VELVET DRIVE 5000 SERIES TRANMISSION SERVICE MANUAL NUMBER 24 Pressure Test 1. Remove transmission temperature switch and install a suitable pressure gauge. 73247 Main Line Pressure Tap - Remove Temperature Switch 2. With boat in water, start engine and run until normal operating temperature is reached. 3.
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Page 842 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 DRIVES Section 8C - Hurth Transmissions Table of Contents Identification ......8C-2 Shift Cable Installation and Adjustment 8C-5...
Page 843 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 Identification The transmission identification plate is located on the top rear of the transmission. HSW 630V – 1,5 Getr.-Nr. = 1,56 = 1,58 71039 MADE IN WEST-GERMANY 72959 Late Style Identification Plate Serial Number and Gear Ratio Specifications Torque Specifications Item / Fastener Location...
Page 844 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 Fluid Specifications Make and Model Capacity Fluid Type ZF (Hurth) 630V 4.2 (4.0) Dexron III Automatic Transmission Fluid 630A 3.2 (3.0) 800A 5.8 (5.5) NOTE: Use dipstick to determine fluid exact level. Warm Fluid Level Check: The transmission should be at operating temperature [190° F (90°...
Page 845 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 Rotation The Hurth transmissions are full power reversing transmissions, allowing a standard (LH rotation) engine to be used for both rotations. Propeller rotation is determined by shift cable attachment at the remote control. CAUTION Avoid severe transmission damage.
Page 846 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 Shift Cable Installation and Adjustment IMPORTANT: Check that shift lever is positioned approximately 10° aft of vertical as shown when in the neutral detent position. Also, ensure that the distance between studs in the following is set at 7-1/8 in. (181 mm). If necessary, loosen clamping bolt and position lever so that dimension “c”...
Page 847 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 2. Place remote control shift lever and transmission shift lever in neutral position. 3. Remove nuts and washers from shift cable attaching studs. 4. Locate center of remote control and control shift cable play (backlash), as follows: a.
Page 848 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 9. If transmission shift lever will position properly in one gear, but not in the other, recheck shift cable adjustment. If transmission shift lever will not position properly in both gears, move transmission shift lever stud from top hole in shift lever to bottom hole and recheck for proper positioning.
Page 849 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 12. Once shift cable adjustment is correct, secure shift cable(s) with hardware as shown, referring to appropriate configuration following: NOTE: To change cable approach direction on single or dual station installations, only the spacer/bushings have to be switched to the opposite stud. The studs are identical. IMPORTANT: Tighten locknut until it contacts and then loosen 1/2 turn.
Page 850 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 71211 72956 Typical Dual Cable - Forward Approach Cable End Guide Cable End Guide Locknut And Washer Spacer (Fits Over Bushings) Bushing Cable Barrel Spacers (Fits Over Stud) Cable Barrel Stud Cable End Guide Stud 50073 72960 Typical Dual Cable - Rear Approach...
Page 851 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 Checking Transmission Fluid Level IMPORTANT: Use only specified transmission fluid; refer to “Transmission Fluid Specifications.” IMPORTANT: The fluid level dipstick is located on the port side of transmission. DO NOT remove T-handle on starboard side of transmission. Check transmission fluid before starting engine each day, as follows: 1.
Page 852 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 Draining Transmission 1. Clean the exterior of transmission before disassembly. NOTE: Later model Hurth transmissions will be equipped with an allen head socket screw on the oil filter cover. 2. Remove oil filter from housing by turning (counterclockwise) and pulling at the same time.
Page 853 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 Filling Transmission IMPORTANT: Use only fluid recommended in “Fluid Specifications.” 1. Fill transmission to proper level, through oil filter cavity. Capacities are listed in “Fluid Specifications.” 2. Install filter as follows: a. Coat O-ring on filter cover with transmission fluid. 27662 Filter Cover O-Ring...
Page 854 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 3. Start engine and run for two minutes to fill system with fluid. 4. Stop engine and check fluid level. Fluid should be between minimum and maximum lines on dipstick. 27661 Typical Hurth Transmission Index 90-861327--1 OCTOBER 1999 Page 8C-13...
Page 855 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 Transmission Removal 1. Disconnect wires from neutral safety switch and audio warning temperature switch. 2. Disconnect seawater hoses from transmission fluid cooler. 72711 Seawater Hoses 3. Remove bolts and locknuts and remove transmission. 72720 Bolts (2), One On Each Side Locknuts (4), Two On Each Side Index...
Page 856 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 Transmission Installation 1. Coat splines on input shaft with Quicksilver Engine Coupler Spline Grease. 71044 Input Shaft 2. Install transmission on flywheel housing and secure with hardware shown. Torque fas- teners to 50 lb-ft (68 Nm). 72720 Bolts (2), One On Each Side Locknuts (4), Two On Each Side...
Page 857 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 3. Connect seawater hoses to transmission fluid cooler and tighten hose clamps securely. 72711 Seawater Hoses Hose Clamps 4. Connect wires to neutral safety switch and to audio warning temperature switch. Coat connections on neutral safety switch with Quicksilver Liquid Neoprene. 50686 Neutral Safety Switch Audio Warning Temperature Switch...
Page 858 HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 Functional Tests 1. Connect a pressure gauge and thermometer to fluid pump at locations shown. 50686 Pressure Gauge (m10x1 Thread - Remove Plug) Thermometer (3/8 In. Thread) - Remove Temperature Sender 2. Perform functional tests as shown in chart following. Refer to “Operating Specifications” for correct readings.
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Page 860 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 DRIVES Section 8D - Drive Shaft / Propeller Shaft Models Table of Contents Torque Specifications ....8D-2 Installation .
Page 861 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 Torque Specifications Fastener Location lb-in. lb-ft Drive Shaft To Bearing Support Flange (MCM Models) Drive Shaft To Output Shaft (MCM Models) Propeller Shaft Coupling To Transmission Coupling (MIE Models) Flywheel Housing To Block (MCM Models) Output Shaft Housing To Flywheel Housing (MCM Models) Engine Coupling Bearing Support Housing Attaching Bolts...
Page 862 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 Flywheel Housing / Output Shaft Housing Repair (MCM Sterndrive Models) NOTICE The following procedure requires removal of the drive shaft. In most cases, because of engine compartment space limitations, the engine also must be removed.
Page 863 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 Removal and Installation 1. Remove drive shaft as outlined following in this section. 2. If engine must be removed, refer to appropriate instructions in SECTION 2 - “Removal and Installation.” Disassembly IMPORTANT: This disassembly procedure, beginning with Step 1.
Page 864 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 Reassembly 1. Install engine coupling. Torque to 35 lb-ft (48 Nm). 2. Install flywheel housing. Torque to 30 lb-ft (41 Nm). 3. Using new gasket, install flywheel cover. Tighten screws securely. IMPORTANT: Groove in outside diameter of ball bearing must align with grease fitting hole.
Page 865 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 2. Suitably mark drive shaft U-joint yokes / flange connections (engine output and drive unit input) to assist in exact same positioning during assembly at engine and transom end. 70237 Engine End Shown (Transom End Similar) Suitable Mark On Flange and Drive Shaft Connection Extension Drive Shaft U-Joint Yoke...
Page 866 Drive Shaft Replacement Drive Shafts MerCruiser furnishes a 58 in. (1473 mm) or 34-1/2 in. (876 mm) long drive shaft with extension shaft models. Some boat manufacturers modify the drive shafts to a shorter length. Because of this, use the following procedure to obtain replacement drive shafts.
Page 867 If a boat manufacturer is currently having extension drive shafts modified, they must be modified by one of Dana Corporation - Spicer Regional Drive Shaft Centers to maintain MerCruiser warranty. The modified drive shaft must meet the following specifications. •...
Page 868 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 2. As shown, attach drive shaft output flange and input shaft flange exactly as marked upon disassembly. Torque fasteners to 50 lb-ft (68 Nm). 70237 Engine End Shown (Transom End Similar) Output Shaft Flange Drive Shaft Bolt 7/16-20 x 1-1/2 In.
Page 869 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 Bearing Support Repair (MCM Sterndrive Models) Removal IMPORTANT: It is not necessary to remove the engine to service the drive shaft and/or bearing support. CAUTION If bearing support is removed, you must remove the sterndrive unit so you can properly align drive unit U-joint centerline with extension drive shaft U-joint center- line.
Page 870 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 Reassembly 1. If removed, install new plug in end of input shaft. 2. Apply Quicksilver Loctite 27131 to outer diameter of new oil seal. 3. Press oil seal into bearing support. Lip of seal faces away from ball bearing. 4.
Page 871 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 Installation 1. Install bearing support assembly (tailstock) on transom plate using hardware as shown. Tighten bolts until they contact. DO NOT TORQUE BOLTS AT THIS TIME. IMPORTANT: The spherical washers MUST be positioned so that the rounded side of the washers are toward the bearing support assembly as shown.
Page 872 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 CAUTION Both attaching bolts MUST be struck firmly in the following step to properly seat spherical washers. If procedure is not followed, difficulty in the installation of the sterndrive unit may be experienced and subsequent damage to the input bearing may result.
Page 873 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 Propeller Shaft (MIE Inboard Models) NOTICE The following information can be used as a guide for determining vibration problems on boats powered by inboard engines (MIE models). For installation, alignment and repairs to shafts, struts, shaft logs and rudders, refer to boat manufacturer’s service manual.
Page 874 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 3. Check output coupling flange of transmission. Checking Coupling Outside Diameter - Rotate One Complete Turn Checking Coupling Face - Rotate One Complete Turn 4. If there is movement in Step 3. replace output coupling. 5.
Page 875 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 2. Check for propeller shaft being bent behind the strut. Metal Straight Edge (Held To Rudder With C-Clamp) - Position Corner Of Straight Edge At Center Of Shaft. Rotate Shaft One Complete Turn. If Shaft Wobbles, Replace Shaft.
Page 876 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 24 Checks Made With Propeller Shaft Removed From Boat 1. Check propeller shaft for straightness. Check at three or four places. If dial indicator deflects over .004 in. (0.1 mm), replace shaft. V-Blocks Dial Indicator Shaft - Rotate One Complete Turn...
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Page 878 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 POWER STEERING SYSTEM Section 9A - Pump And Related Components Table of Contents Torque Specifications ....9A-2 Important Service Information .
Page 879 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 Torque Specifications Fastener Location lb-in. lb-ft Crankshaft Pulley To Torsional Damper Torsional Damper To Crankshaft Pump Mounting Bracket To Engine Power Steering Hose Fittings Tools Description Part Number Pulley Installer 91-93656A1 Special Tools Description Part Number Kent-Moore Special Tools...
Page 880 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 Precautions CAUTION Do not operate engine without cooling water being supplied to water pickup pump or water pump impeller will be damaged and subsequent overheating damage to engine may result. WARNING Always disconnect battery cables from battery before working on engine to prevent fire or explosion.
Page 881 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 Serpentine Belt Routing S/N 0L618999 and Below Alpha With Power Steering Bravo With Power Steering Alpha With Closed Cooling Bravo Without Power Steering Without Power Steering Alpha With Closed Cooling Bravo With Closed Cooling and Power Steering and Power Steering Index...
Page 882 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 Serpentine Belt Routing (Continued) S/N 0L619000 and Above 76503 76502 Alpha With Power Steering Bravo With Power Steering 76463 76445 Alpha Without Power Steering Bravo Without Power Steering Index 90-861327--1 OCTOBER 1999 Page 9A-5...
Page 883 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 Serpentine Belt Adjustment IMPORTANT: If a belt is to be reused, it should be installed in the same direction of rotation as before. Removal 1. Remove drive belt as follows: NOTE: The upper, starboard idler pulley is the belt adjustment pulley. a.
Page 884: Pump Pulley Replacement
PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 Important Service Information Pump Pulley Replacement REMOVAL NOTE: Serpentine belt pulley requires a special puller tool. See your local automotive repair dealer for appropriate tool or use Snap-On P/N CJ124A. 1. Install appropriate puller on end of pulley and shaft as shown. 2.
Page 885 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 Testing and Repair Refer to appropriate MerCruiser Sterndrive Service Manual. Checking Pump Fluid Level Refer to SECTION 1B “Maintenance.” Filling and Air Bleeding System Refer to SECTION 1B “Maintenance.” Pump Assembly Removal 1.
Page 886 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 2. Remove the high pressure hose and return hose from the power steering pump. 75228 Power Steering Pump Typical Location Return Hose High Pressure Hose 3. Remove mounting fasteners from pump. 75798 75228 Power Steering Pump Typical Location Bolts...
Page 887 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 Installation IMPORTANT: Be careful to not cross-thread or overtighten hose fittings. 1. Place the power steering pump on the bracket and install the screws and nut. Torque to 30 lb-ft (41 Nm). 75798 75228 Power Steering Pump Typical Location...
Page 888 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 Hydraulic Hoses and Fluid Cooler The following information is provided to assist in replacement of power steering fluid hoses and to assure proper routing and connection to the cooler. Replace high or low pressure hoses following: IMPORTANT: Make hydraulic connections as quickly as possible to prevent fluid leakage.
Page 889 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 INSTALLATION CAUTION Route hoses exactly as shown below. This will help avoid stress on the hose fittings and will help avoid kinks in the hoses. IMPORTANT: Be careful to not cross-thread or overtighten hose fittings. 1.
Page 890 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 Low Pressure Hose (Cooler-to-Pump) REMOVAL NOTE: Catch fluid that drains from hose, cooler and pump in a suitable container. 1. Loosen hose clamp and remove hose from fluid cooler. 75595 Hose 2. Loosen hose clamp and remove hose from back of pump. 75228 Power Steering Pump Typical Location Hose Clamp...
Page 891 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 INSTALLATION 1. Using hose clamp, install new hose on back of pump. Tighten clamp securely. 75228 Power Steering Pump Typical Location Hose Clamp Hose 2. Using hose clamp, install hose on fluid cooler. Tighten clamp securely. 75595 Hose 3.
Page 892 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 Low Pressure Hose (Control Valve-to-Cooler) REMOVAL NOTE: Catch fluid that drains from hose, cooler and pump in a suitable container. 1. Loosen hose clamp and remove hose from fluid cooler. 75595 Hose 2.
Page 893 PUMP AND RELATED COMPONENTS SERVICE MANUAL NUMBER 24 INSTALLATION CAUTION Route hoses exactly as shown below. This will help avoid stress on the hose fittings and will help avoid kinks in the hoses. IMPORTANT: Be careful to not cross-thread or overtighten hose fittings. 1.
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This manual is also suitable for:

350 cid (5.7l)5.0 mpi

MerCruiser 305 CID (5.0L) Service Manual

Important Information

Section 2

Section 3

Removal and Installation

Section 2A - MCM Models

SECTION 2B - MIE Models

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Summary of Contents for MerCruiser 305 CID (5.0L)