Page 1: Table Of Contents
SERVICE MANUAL NUMBER 25 MAINTENANCE IMPORTANT INFORMATION Section 1B - Maintenance Table of Contents Tools ......1B-2 Closed Cooling System .
Page 2: Tools
MAINTENANCE SERVICE MANUAL NUMBER 25 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 Teflon 92-825407A3 Loctite Pipe Sealant With Teflon Obtain Locally Quicksilver U-Joint and Gimbal Bearing Grease 92-828052A2...
Page 3: 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 4: Scheduled Maintenance
MAINTENANCE SERVICE MANUAL NUMBER 25 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 5: 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 6: Fluid Capacities
MAINTENANCE SERVICE MANUAL NUMBER 25 Fluid Capacities NOTICE Unit Of Measurement: U.S. Quarts (Liters) All capacities are approximate fluid measures. Sterndrive Engines Model All Models Crankcase Oil (With Filter) 4-1/2 (4.3) Seawater Cooling System 15 (14.1) Closed Cooling System 20 (19) Always use dipstick to determine exact quantity of oil or fluid required.
Page 7: 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 in an area where the product is operated continuously (year-round operation), you should contact your dealer at the end of the first 100 hours of operation, or once yearly, whichever occurs first.
Page 8: 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 9 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 10: Test For Alcohol Content In Gasoline 1B-10
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 11: 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 12: Checking Engine Oil Level / Filling
MAINTENANCE SERVICE MANUAL NUMBER 25 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 13: Changing Water Separating Fuel Filter
SERVICE MANUAL NUMBER 25 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 14 MAINTENANCE SERVICE MANUAL NUMBER 25 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 15: Power Steering System
SERVICE MANUAL NUMBER 25 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 16: Filling And Bleeding
MAINTENANCE SERVICE MANUAL NUMBER 25 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 17: Closed Cooling System
SERVICE MANUAL NUMBER 25 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 18: Flushing System
MAINTENANCE SERVICE MANUAL NUMBER 25 Flushing System 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 19 SERVICE MANUAL NUMBER 25 MAINTENANCE BOAT IN WATER 1. Raise drive unit to full UP / OUT 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 20: Lubrication
MAINTENANCE SERVICE MANUAL NUMBER 25 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 MCM (STERNDRIVE) MODELS 1. Lubricate pivot points and guide contact surfaces with SAE 30W motor oil. 72016 Typical Shift Cable Pivot Points...
Page 21: Engine Coupler / U-Joint Shaft Splines
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 22: Sterndrive Drive Shaft Extension Models
MAINTENANCE SERVICE MANUAL NUMBER 25 Sterndrive Drive Shaft Extension Models 72018 72028 Transom End Engine End Grease Fitting 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.
Page 23: Top Mounted Flame Arrestor
SERVICE MANUAL NUMBER 25 MAINTENANCE Top Mounted Flame Arrestor 1. Remove flame arrestor cover. 2. Remove crankcase ventilation hose from fitting on side of flame arrestor housing. 3. Remove flame arrestor. 76501 Flame Arrestor 4. Clean flame arrestor in solvent. Blow dry with compressed air. 5.
Page 24: Serpentine Belt Routing
MAINTENANCE SERVICE MANUAL NUMBER 25 Serpentine Belt Routing S/N 0L619083 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 1B-24...
Page 25: S/N 0L619084 And Above
SERVICE MANUAL NUMBER 25 MAINTENANCE Serpentine Belt Routing (Continued) S/N 0L619084 and Above 76503 76502 Alpha With Power Steering Bravo With Power Steering 76463 76445 Alpha Without Power Steering Bravo Without Power Steering Index 90-861328--1 NOVEMBER 1999 Page 1B-25...
Page 26: Inspection
MAINTENANCE SERVICE MANUAL NUMBER 25 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 27: Ignition Timing
SERVICE MANUAL NUMBER 25 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. 74908 5/8 in. Locking Nut 5/16 in. Adjusting Stud Ignition Timing Thunderbolt V Models 1.
Page 28: Efi
MAINTENANCE SERVICE MANUAL NUMBER 25 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 wiring harness.
Page 29: Cold Weather Or Extended Storage
SERVICE MANUAL NUMBER 25 MAINTENANCE Cold Weather or Extended Storage Precautions WARNING Always disconnect battery cables from battery BEFORE working on fuel system to prevent fire or explosion. WARNING BE CAREFUL while working on fuel system; gasoline is extremely flammable and highly explosive under certain conditions.
Page 30 MAINTENANCE SERVICE MANUAL NUMBER 25 CAUTION Seawater section of cooling system MUST BE COMPLETELY drained for winter storage, or immediately after cold weather use, if the possibility of freezing temper- atures exists. Failure to comply may result in trapped water causing freeze and/or corrosion damage to engine.
Page 31: Power Package Layup
Refer to “Precautions” in this section BEFORE proceeding. 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 32 MAINTENANCE SERVICE MANUAL NUMBER 25 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 33: Draining Instructions
SERVICE MANUAL NUMBER 25 MAINTENANCE Draining Instructions DRAINING SEAWATER (RAW-WATER) COOLED MODELS NOTICE Refer to “Precautions” in this section BEFORE proceeding. IMPORTANT: Engine must be as level as possible to ensure complete draining of cooling system. 1. Remove drain plugs from bottom of port and starboard manifold fittings. 2.
Page 34 MAINTENANCE SERVICE MANUAL NUMBER 25 3. 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 35 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 seawater section of the cooling system for cold weather or extended storage.
Page 36 MAINTENANCE SERVICE MANUAL NUMBER 25 DRAINING SEAWATER SECTION OF CLOSED COOLED (COOLANT) MODELS NOTICE Refer to “Precautions” in this section BEFORE proceeding. IMPORTANT: Drain seawater section of closed cooling system only. IMPORTANT: Engine must be as level as possible to ensure complete draining of cooling system.
Page 37 SERVICE MANUAL NUMBER 25 MAINTENANCE 3. Remove seawater pump inlet hose. 75533 Seawater Inlet Hose Hose To Cooler 4. 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 38: Draining Sterndrive
MAINTENANCE SERVICE MANUAL NUMBER 25 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 39: Recommissioning
SERVICE MANUAL NUMBER 25 MAINTENANCE Recommissioning NOTICE Refer to “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. Inspect serpentine drive belt for condition and proper tension. 4.
Page 40 MAINTENANCE SERVICE MANUAL NUMBER 25 THIS PAGE IS INTENTIONALLY BLANK Index Page 1B-40 90-861328--1 NOVEMBER 1999...

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