Mercury 25 Jet 4-Stroke Manual

Table of Contents

Quick Links

Welcome Aboard!

Proper care and maintenance is an important part in keeping

your Mercury Product operating at peak efficiency for

maximum performance and economy. The enclosed Owner's

Registration Card is your key to trouble‑free family fun. Refer

to your Operation and Maintenance Manual for full details

of your warranty coverage.

Details

your

www.marinepower.com where country maps and full

contact information are displayed.

Is your engine properly registered for warranty purpose?

Please check on www.marinepower.com. If necessary,

please contact your local dealer.

Declaration of Conformity

This outboard motor's serial number plate contains in the

lower left hand corner the CE mark. This outboard motor

manufactured by Mercury Marine, Fond du Lac, Wisconsin,

USA or Marine Power Europe Inc., Park Industriel, de

Petit‑Rechain, Belgium complies with the requirements of the

following directives by meeting the associated standards, as

amended:

Recreational Craft Directive:

Owner's manual (A.2.5)

Handling characteristics (A.4)

Outboard engine starting (A.5.1.4) ISO 11547

Fuel tanks (A.5.2.2)

General steering system (A.5.4.1) ABYC P‑17

Exhaust emission requirements (B.

Owner's manual (B.4)

Noise emission levels (C.1)

The notified body responsible for EC‑Type Examination for the engine

exhaust emissions assessment under Modules B+C of Directive 2003/44/

EC and for noise emission assessment under Module Aa of Directive

2003/44/EC is:

nearest

dealer

2003/44/EC amending 94/25/EC

ISO 10240

ISO 8665

ISO 13591; ISO 8469

ISO 8178

ISO 8665

ISO 14509

can

found

Table of Contents

Summary of Contents for Mercury 25 Jet 4-Stroke

Page 1 Welcome Aboard! Proper care and maintenance is an important part in keeping your Mercury Product operating at peak efficiency for maximum performance and economy. The enclosed Owner's Registration Card is your key to trouble‑free family fun. Refer to your Operation and Maintenance Manual for full details of your warranty coverage.
Page 2 This declaration is issued under the sole responsibility of Mercury Marine and Marine Power Europe. Patrick C. Mackey President, Mercury Marine, Fond du Lac, WI USA on December 16, 2005. European Regulations Contact: Regulations and Product Safety Department, Mercury Marine,...
Page 3: Table Of Contents
Protecting People In The Water..........19 Wave And Wake Jumping............20 Safety Instructions For Hand Tilled Outboards......21 Exhaust Emissions..............21 Selecting Accessories For Your Outboard......... 23 Safe Boating Suggestions............23 Recording Serial Number............26 25 Jet 4-Stroke Specifications - International......26 Component Identification............28 TRANSPORTING Trailering Boat/Outboard............30...
Page 4 TABLE OF CONTENTS FUEL & OIL Fuel Recommendations.............31 Filling Fuel Tank................33 Engine Oil Recommendations...........33 Checking And Adding Engine Oil..........34 FEATURES & CONTROLS Remote Control Features............36 Tiller Handle Models..............37 Power Trim And Tilt (If Equipped)..........43 Warning System................46 Replaceable Jet Drive Shear Key..........48 OPERATION Pre-Starting Check List..............49 Operating In Freezing Temperatures.........
Page 5 TABLE OF CONTENTS MAINTENANCE Outboard Care................65 EPA Emissions................66 Inspection and Maintenance Schedule........66 Top Cowl Removal and Installation...........68 Exterior Care................69 Worn/Dull Impeller..............69 Impeller Clearance Adjustment..........70 Impeller Removal and Installation..........71 Shift Link Rod Adjustment............76 Battery Inspection ..............77 Fuel System................78 Steering Link Rod Fasteners.............79 Corrosion Control Anode............80 Spark Plug Inspection And Replacement........82...
Page 6 OWNER SERVICE ASSISTANCE Local Repair Service..............96 Service Away From Home............96 Parts And Accessories Inquiries..........96 Service Assistance..............96 Mercury Marine Service Offices..........97 ENGINE INSTALLATION Installation Information............... 99 Top Cowl Removal And Installation.........100 Lifting Outboard...............101 Determining the Mounting Height of the Outboard ....101 Fastening the Outboard............103...
Page 7: Warranty Information
1. You may change your address at any time, including at time of warranty claim, by calling Mercury Marine or sending a letter or fax with your name, old address, new address, and engine serial number to Mercury Marine’s warranty registration department.
Page 8: Warranty Registration Outside The United States And Canada
2. To be eligible for warranty coverage, the product must be registered with Mercury Marine. At the time of sale, the dealer should complete the warranty registration and immediately submit it to Mercury Marine via MercNET, E‑mail, or mail.
Page 9: Fourstroke Outboard Limited Warranty United States, Canada, Europe, Confederation Of Independent States, Middle-East And Africa
Outside the United States, Canada, Europe, Confederation of Independent States, Middle‑East and Africa ‑ check with your local distributor. WHAT IS COVERED: Mercury Marine warrants its new Outboard and Jet Products to be free of defects in material and workmanship during the period described below.
Page 10 WARRANTY COVERAGE: Warranty coverage is available only to retail customers that purchase from a Dealer authorized by Mercury Marine to distribute the product in the country in which the sale occurred, and then only after the Mercury Marine specified pre–delivery inspection process is completed and documented.
Page 11 Mercury dealer authorized to service the product. If purchaser cannot deliver the product to such a dealer, written notice must be given to Mercury. We will then arrange for the inspection and any covered repair. Purchaser in that case shall pay for all related transportation charges and/or travel time.
Page 12: Year Limited Warranty Against Corrosion
No individual or entity, including Mercury Marine authorized dealers, has been given authority by Mercury Marine to make any affirmation, representation or warranty regarding the product, other than those contained in this limited warranty, and if made, shall not be enforceable against Mercury Marine.
Page 13 WARRANTY COVERAGE: Warranty coverage is available only to retail customers that purchase from a Dealer authorized by Mercury Marine to distribute the product in the country in which the sale occurred, and then only after the Mercury Marine specified pre‑delivery inspection process is completed and documented.
Page 14 Mercury dealer authorized to service the product. If purchaser cannot deliver the product to such a dealer, written notice must be given to Mercury. We will then arrange for the inspection and any covered repair. Purchaser in that case shall pay for all related transportation charges and/or travel time.
Page 15 Mercury Precision Parts or Quicksilver MerCathode system and/ or Galvanic Isolator. Corrosion damage caused by improper application of copper base anti‑fouling paints is also not covered by this limited warranty.
Page 16: Warranty Coverage And Exclusions
WARRANTY INFORMATION Warranty Coverage And Exclusions The purpose of this section is to help eliminate some of the more common misunderstandings regarding warranty coverage. The following information explains some of the types of services that are not covered by warranty. The provisions set forth following have been incorporated by reference into the Three Year Limited Warranty Against Corrosion Failure, the International Limited Outboard Warranty, and the United States and Canada Limited...
Page 17 8. Use of other than Mercury Precision or Quicksilver parts when making warranty repairs. 9. Oils, lubricants or fluids changed as a matter of normal...
Page 18 WARRANTY INFORMATION 16. Our limited warranty does not apply to any damage to our products caused by the installation or use of parts and accessories which are not manufactured or sold by us. Failures which are not related to the use of those parts or accessories are covered under warranty if they otherwise meet the terms of the limited warranty for that product.
Page 19: General Information
GENERAL INFORMATION Boater's Responsibilities The operator (driver) is responsible for the correct and safe operation of the boat and safety of its occupants and general public. It is strongly recommended that each operator (driver) read and understand this entire manual before operating the outboard. Be sure at least one additional person on board is instructed in the basics of starting and operating the outboard and boat handling in case the driver is unable to operate the boat.
Page 20: Boat Horsepower Capacity
For additional information, obtain a copy of our Hi‑Performance Boat Operation booklet from your dealer, distributor, or Mercury Marine. ob00307...
Page 21: Outboard Remote Control Models
GENERAL INFORMATION Outboard Remote Control Models The remote control connected to your outboard must be equipped with a start in neutral only protection device. This prevents the engine from starting when the shift is actuated in any position other than neutral. WARNING Avoid serious injury or death from a sudden unexpected acceleration when starting your engine.
Page 22: Lanyard Stop Switch
GENERAL INFORMATION WARNING Disengagement of a steering link rod can result in the boat taking a full, sudden, sharp turn. This potentially violent action can cause occupants to be thrown overboard exposing them to serious injury or death. 9938 Self‑locking nuts Lanyard Stop Switch The purpose of a lanyard stop switch is to turn off the engine when the operator moves far enough away from the operator's position...
Page 23 GENERAL INFORMATION lanyard cord usually between 122 and 152 cm (4 and 5 feet) in length when stretched out, with an element on one end made to be inserted into the switch and a snap on the other end for attaching to the operator. The lanyard is coiled to make its at‑rest condition as short as possible to minimize the likelihood of lanyard entanglement with nearby objects.
Page 24 GENERAL INFORMATION While activation of the lanyard stop switch will stop the engine immediately, a boat will continue to coast for some distance depending upon the velocity and degree of any turn at shut down. However, the boat will not complete a full circle. While the boat is coasting, it can cause injury to anyone in the boat's path as seriously as the boat would when under power.
Page 25: Protecting People In The Water
GENERAL INFORMATION Protecting People In The Water WHILE YOU ARE CRUISING It is very difficult for a person standing or floating in the water to take quick action to avoid a boat heading in his/her direction, even at slow speed. 21604 Always slow down and exercise extreme caution when boating in an area where there might be people in the water.
Page 26: Wave And Wake Jumping
GENERAL INFORMATION Wave And Wake Jumping Operating recreational boats over waves and wake is a natural part of boating. However, when this activity is done with sufficient speed to force the boat hull partially or completely out of the water, certain hazards arise, particularly when the boat re‑enters the water.
Page 27: Safety Instructions For Hand Tilled Outboards
GENERAL INFORMATION Safety Instructions For Hand Tilled Outboards No person or cargo should occupy the area directly in front of the outboard while the boat is in motion. If an underwater obstacle is struck, the outboard will tilt up and could seriously injure anyone occupying this area.
Page 28 GENERAL INFORMATION WARNING Avoid the combination of a running engine and poor ventilation. Prolonged exposure carbon monoxide sufficient concentration can lead to unconsciousness, brain damage, or death. GOOD VENTILATION Ventilate passenger area, open side curtains, or forward hatches to remove fumes. 21622 Example of desired air flow through the boat POOR VENTILATION...
Page 29: Selecting Accessories For Your Outboard
Some accessories not manufactured or sold by Mercury Marine are not designed to be safely used with your outboard or outboard operating system. Acquire and read the installation, operation, and maintenance manuals for all your selected accessories.
Page 30 GENERAL INFORMATION Know and obey all nautical rules and laws of the waterways. Boat operators should complete a boating safety course. Courses are offered in the U.S.A. by 1) The U.S. Coast Guard Auxiliary, 2) The Power Squadron, 3) The Red Cross and 4) any state boating law enforcement agency.
Page 31 GENERAL INFORMATION Watch for boat movement in neutral. When the jet drive is in neutral, the drive impeller continues to rotate. Although the approximate balancing of forward and reverse thrust will minimize boat movement, the boat may tend to move slowly forward or backward.
Page 32: Recording Serial Number
GENERAL INFORMATION Recording Serial Number It is important to record this number for future reference. The serial number is located on the outboard as shown. OTXXXXXX XXXX 24800 Serial number Year manufactured Model designation Certified Europe Insignia (as applicable) 25 Jet 4‑Stroke Specifications ‑ International Models Horsepower Kilowatts...
Page 33 GENERAL INFORMATION Models Recommended lubricant for Refer to Maintenance the jet pump driveshaft bearing Engine Oil Capacity 1.8 liter (1.9 quarts) 465 Marine Cranking Amps (MCA) or 350 Cold Battery Rating Cranking Amps (CCA) Sound at Drivers Ear (ICOMIA 39‑94) 4‑Stroke...
Page 34: Component Identification
GENERAL INFORMATION Component Identification TILLER HANDLE/GAS ASSIST MODEL 24805 Top cowl Reverse gate Manual start handle Water outlet housing Engine stop switch Chaps Throttle friction -Water pump indicator adjustment knob hole Gear shift Cowl latch Tilt support lever Warning light Gas tilt assist lever Electric start button (electric start models)
Page 35 GENERAL INFORMATION POWER TRIM/REMOTE CONTROL MODEL 24827 Transom brackets Chaps Tilt support lever Water outlet housing Top cowl Reverse gate Cowl latch Water intake housing Bottom cowl Jet drive housing Auxiliary tilt switch...
Page 36: Transporting
TRANSPORTING Trailering Boat/Outboard The boat should be trailered with the outboard tilted down in a vertical operating position. IMPORTANT: Do not rely on the power trim/tilt system or tilt support lever to maintain proper ground clearance for trailering. The outboard tilt support lever is not intended to support the outboard for trailering.
Page 37: Fuel & Oil
FUEL RATINGS Mercury Marine engines will operate satisfactorily when using a major brand of unleaded gasoline meeting the following specifications: USA and Canada ‑ having a posted pump Octane Rating of 87 (R +M)/2 minimum.
Page 38 FUEL & OIL The fuel system components on your Mercury Marine engine will withstand up to 10% alcohol content in the gasoline. We do not know what percentage your boat's fuel system will withstand. Contact your boat manufacturer for specific recommendations on the boat's fuel system components (fuel tanks, fuel lines, and fittings).
Page 39: Filling Fuel Tank
PORTABLE FUEL TANK PLACEMENT IN THE BOAT Place the fuel tank in the boat so the vent is higher than the fuel level under normal boat operating conditions. Engine Oil Recommendations We recommend the use of Mercury or Quicksilver NMMA FC‑W certified 10W‑30 4‑Stroke...
Page 40: Checking And Adding Engine Oil
FUEL & OIL IMPORTANT: The use of detergent oils, multi‑viscosity oils (other than Mercury or Quicksilver NMMA FC‑W certified oil or a major brand NMMA FC‑W certified oil), synthetic oils, low quality or oils that contain solid additives are not recommended.
Page 41 FUEL & OIL 3. Pull the dipstick back out again and observe the oil level. Oil must be between full mark and add mark. If the oil level is low, remove the oil fill cap and fill to (but not over) the upper oil level.
Page 42: Features & Controls
FEATURES & CONTROLS Remote Control Features Your boat may be equipped with one of the Mercury Precision or Quicksilver remote controls shown. If not, consult your dealer for a description of the functions and operations of the remote control. ob00329 Control handle ‑...
Page 43: Tiller Handle Models
FEATURES & CONTROLS Tiller Handle Models FEATURES • Steering friction adjustment ‑ Adjust this lever to achieve the desired steering friction (drag) on the tiller handle. Move the lever to the left to tighten friction or move to the right to loosen friction.
Page 44 FEATURES & CONTROLS • Electric start button (Electric start models) ‑ Press to start the engine. 15898 • Tiller handle ‑ The tiller handle can be tilted 180° for convenient handling during transportation and storage. ob01153...
Page 45 FEATURES & CONTROLS • Tiller lock release lever ‑ Push the lever to move the tiller handle from one position to another. 3274 • Tiller handle lock cap ‑ Remove the lock cap on top of the tiller handle to lock in the up position. Push the tiller lock release lever to release the handle from the locked up position.
Page 46 FEATURES & CONTROLS • Throttle grip friction knob ‑ Turn the friction knob to set and maintain the throttle at desired speed. Turn the knob clockwise to tighten the friction or turn the knob counterclockwise to loosen the friction. ob01156 Loosen friction Tighten friction (counterclockwise)
Page 47 FEATURES & CONTROLS Move the lock lever to the free position. Tilt the outboard to the desired position and lock in place by moving the tilt lock lever back to the lock position. FREE LOCK 10257 Free position Lock position TILTING OUTBOARD TO FULL UP POSITION 1.
Page 48 FEATURES & CONTROLS 2. Move the lock lever to the lock position. 9703 OPERATING ANGLE ADJUSTMENT The transom brackets have four holes for adjusting the vertical operating angle (forward stop movement) of the outboard. Use the tilt pin for adjustments in the four holes. FREE LOCK 10290...
Page 49: Power Trim And Tilt (If Equipped)
FEATURES & CONTROLS Power Trim And Tilt (If Equipped) POWER TRIM AND TILT Your outboard has a trim/tilt control called power trim. This enables the operator to easily adjust the position of the outboard by pressing the trim switch. Moving the outboard in closer to the boat transom is called trimming in or down.
Page 50 FEATURES & CONTROLS When planing, the outboard should be positioned vertical or tilted in toward the boat to provide a scooping angle on the water intake grate. Tilting the outboard out beyond a vertical position reduces the scoop angle and can cause impeller slippage and cavitation burns on the impeller blades.
Page 51 FEATURES & CONTROLS 1. Turn manual tilt release valve turns counterclockwise. This allows manual tilting of the outboard. Tilt the outboard to the desired position and tighten the manual tilt release valve. 9976 AUXILIARY TILT SWITCH The auxiliary tilt switch can be used to tilt the outboard up or down using the power trim system.
Page 52: Warning System
FEATURES & CONTROLS Warning System WARNING HORN Remote control models have a warning horn located inside the remote control or connected to the ignition key switch. Tiller handle models have a warning horn located in the engine cowl. WARNING LIGHT The warning light will turn on or flash to alert the operator to the warning system situations listed the the following chart.
Page 53 FEATURES & CONTROLS Warning System Engine Warning Speed Function Sound Description Light Limited to 2800 RPM Engine speed Water temp or will limited. Intermittent MAP sensor out Flashes Consult your short beep of range dealer for assistance ENGINE OVERHEAT If the engine overheats, immediately reduce throttle speed to idle. Shift the outboard into neutral and check for a steady stream of water coming out of the water pump indicator hole.
Page 54: Replaceable Jet Drive Shear Key
FEATURES & CONTROLS LOW OIL PRESSURE The warning system is activated if the oil pressure drops too low. First, stop the engine and check the oil level. Add oil if necessary. If the oil is at the recommended level and the warning horn continues to sound, consult your dealer.
Page 55: Operation
OPERATION Pre‑Starting Check List • Operator knows safe navigation, boating, and operating procedures. • An approved personal flotation device of suitable size for each person aboard and readily accessible (it is the law). • A ring type life buoy or buoyant cushion designed to be thrown to a person in the water.
Page 56: Operating In Salt Water Or Polluted Water
Wash down the outboard exterior and flush out the exhaust outlet of the jet drive with fresh water after each use. Each month, spray Mercury Precision or Quicksilver Corrosion Guard on external metal surfaces. Operating In Shallow Water The life of the impeller and water intake can be greatly increased by avoiding the intake of sand and gravel.
Page 57 OPERATION The driveshaft driven impeller draws water up through the water intake and then redirects it at a high pressure through the water outlet nozzle to create forward thrust. To obtain reverse, the reverse gate moves over the outlet nozzle to direct the water in the opposite direction.
Page 58: Stopping The Boat In An Emergency
OPERATION The jet drive is always drawing water into the housing when the engine is running. Do not operate the jet drive with the grate removed from the water intake. Keep hands, feet, hair, loose clothing, life jackets, etc., away from the water intake. Never insert an object into the water intake or water outlet nozzle when the engine is running.
Page 59: Mooring The Boat
OPERATION WARNING Avoid injury, death or property damage resulting from collision due to loss of directional control. Directional control is derived from the water jet thrust. Caution should be exercised when maneuvering at higher speeds in areas where debris (weeds, logs, gravel, etc.) could be picked up into the jet drive.
Page 60: Clearing A Lodged Impeller
OPERATION Clearing A Lodged Impeller WARNING If the flywheel is rotated to free a lodged impeller, there is the possibility that the engine will crank over and start. To prevent this type of accidental engine starting and possible serious injury, always turn the ignition key or lanyard stop switch to the "OFF"...
Page 61: Engine Break-In Procedure
OPERATION 2. Check the engine oil level. 9601 3. Ensure the driveshaft bearing on the jet drive is lubricated. Refer to Maintenance - Lubrication Points. ob01394 Engine Break‑in Procedure CAUTION Severe damage to the engine can result by not complying with the engine break‑in proceedure.
Page 62: Starting The Engine - Remote Control Models
OPERATION Starting The Engine ‑ Remote Control Models Before starting, read the pre‑starting checklist, special operating instructions, and engine break‑in procedure in the Operation section. CAUTION Never start or operate your outboard (even momentarily) without the water intake housing in the water to prevent damage to the water pump (running dry) or overheating of the engine.
Page 63 OPERATION 4. Shift the outboard to the neutral ("N") position. ob00351 5. Move the neutral fast idle speed feature to the fully closed position. NOTE: To start a flooded engine, advance the neutral fast idle speed feature to the maximum fast idle speed position and continue to crank the engine for starting.
Page 64: Starting The Engine - Tiller Handle Models
OPERATION Starting The Engine ‑ Tiller Handle Models Before starting, read the pre‑starting checklist, special operating instructions, and engine break‑in procedure in the Operation section. CAUTION Never start or operate your outboard (even momentarily) without the water intake housing in the water to prevent damage to the water pump (running dry) or overheating of the engine.
Page 65 OPERATION 4. Set the tiller handle grip to the neutral start position. START 24834 5. Set the gear shift to the neutral "N" position. 24835 6. Position the tilt lock lever to the lock position. FREE LOCK 10251 7. Manual starting models ‑ Pull the starter rope slowly until the starter engages, then pull rapidly to crank the engine.
Page 66: Gear Shifting
OPERATION 8. Electric starting models ‑ Push the starter button and crank the engine. Release the button when the engine starts. Do not operate the starter motor continuously for longer than ten seconds at a time. If the engine fails to start in ten seconds, wait 30 seconds and try again.
Page 67 OPERATION • The outboard has three gear shift positions to provide operation: forward (F), neutral (N), and reverse (R). • Tiller handle models ‑ Reduce the engine speed to idle before shifting. START 24834 24835 • Remote control models ‑ When shifting, always stop at the neutral position and allow the engine speed to return to idle.
Page 68: Stopping The Engine
OPERATION Stopping The Engine Reduce engine speed and shift outboard to neutral position. Push in the stop switch or move the lanyard stop switch to the "OFF" position. ob00361 Emergency Starting If the starter system fails, the engine can be started using the spare starter rope (provided).
Page 69 OPERATION WARNING When using emergency starter rope to start engine, the start in gear protection device is inoperative. Make sure to set the outboard gear shift into neutral to prevent outboard from starting in gear. Sudden unexpected acceleration could result in serious injury or death.
Page 70 OPERATION 5. Pull the starter rope to start the engine. 10006...
Page 71: Outboard Care
Save all maintenance work orders and receipts. SELECTING REPLACEMENT PARTS FOR YOUR OUTBOARD We recommend using original Mercury Precision or Quicksilver replacement parts and Genuine Lubricants. WARNING Using a replacement part that is inferior to the original part could...
Page 72: Epa Emissions
MAINTENANCE EPA Emissions EMISSION CERTIFICATION LABEL An emission certification label, showing emission levels and engine specifications directly related to emissions, is placed on the engine at time of manufacture. 21096 Idle speed Family number Engine horsepower Maximum emission output for the engine Piston displacement family Part number...
Page 73 MAINTENANCE • Check the steering system for binding or loose components. • Visually check the steering link rod fasteners for proper tightness. See Steering Link Rod Fasteners. • Make sure the driveshaft bearing on the jet drive is lubricated. See Lubrication Points. AFTER EACH USE AND AFTER EVERY 10 HOURS OF OPERATION •...
Page 74: Top Cowl Removal And Installation
MAINTENANCE • Check and adjust valve clearance, if necessary. • Check the power trim fluid. See Checking Power Trim Fluid. • Inspect the battery. See Battery Inspection. • Check the control cable adjustments. • Inspect the timing belt. See Timing Belt Inspection. •...
Page 75: Exterior Care
MAINTENANCE 2. Lift rear of cowl and disengage front hook. 10191 INSTALLATION 1. Lower the top cowl over the engine. Bring the front of the cowl down first and engage the front hook, then lower the cowl into its seated position with the bottom cowl. 2.
Page 76: Impeller Clearance Adjustment
MAINTENANCE Check the impeller blades occasionally for damage. Use a flat file to resharpen the leading edges. Sharpen to a 0.8 mm (1/32 in.) radius by removing material from bottom side only. ob01409 Leading edge Top side lifting angle Impeller Clearance Adjustment The impeller should be adjusted so there is approximately 0.8 mm (0.03 in.) clearance between the impeller edge and liner.
Page 77: Impeller Removal And Installation
MAINTENANCE As the blades wear, shims located in the stack outside of the impeller can be transferred behind the impeller. This will move the impeller further down into the tapered liner to reduce the clearance. ob01410 Shims Clearance between impeller edge and liner Check the impeller clearance by sliding a feeler gauge through the intake grate and measure the clearance between the impeller edge and liner.
Page 78 MAINTENANCE 1. Shift the outboard to the neutral position. 24835 2. Position the key switch or lanyard stop switch to the "OFF" position. 3. Remove the spark plug leads to prevent the engine from starting. ob00375 4. Remove the six screws securing the water intake housing, and remove the water intake housing.
Page 79 MAINTENANCE 5. Straighten the bent tabs on the impeller nut retainer and remove the impeller nut. ob01412 Tabs Impeller nut 6. Pull the impeller straight off the shaft. If the impeller is tight, use a hammer and a block of wood to rotate the impeller clockwise on the shaft until the keyway is directly above the flat on the shaft.
Page 80 MAINTENANCE 2. Place the plastic sleeve inside the impeller and install impeller, shear key, shims, nut retainer, and impeller nut. ob01413 Plastic sleeve Shims Impeller Nut retainer Shear key Impeller nut 3. Turn the nut tight on the shaft to remove any play between the impeller and shaft.
Page 81 MAINTENANCE 4. Temporarily reinstall the water intake housing in order to check for impeller clearance. The clearance between the impeller and liner should be 0.08 mm (0.03 in.). Shim washers can be transferred to either side of the impeller to raise or lower the impeller to the correct clearance setting.
Page 82: Shift Link Rod Adjustment
MAINTENANCE NOTE: If the outboard is used in salt water, apply Quicksilver or Mercury Precision Anti‑Corrosion Grease around the entire mounting flange on the water intake housing and also to the threads on the six mounting bolts. Tube Ref No.
Page 83: Battery Inspection
MAINTENANCE CHECKING SHIFT LINK ROD ADJUSTMENT Check the shift link rod adjustment in forward shift position. The correct adjustment will position the shift cam far enough on the roller in order to lock the reverse gate into forward position. The reverse gate should not be able to be forced up towards neutral.
Page 84: Fuel System
MAINTENANCE 4. Battery cable terminals should be clean, tight, and correctly installed. Positive to positive and negative to negative. 5. Make sure the battery is equipped with a non‑conductive shield to prevent accidental shorting of battery terminals. Fuel System WARNING Avoid serious injury or death from gasoline fire or explosion.
Page 85: Steering Link Rod Fasteners
MAINTENANCE 3. Inspect the filter element. If replacement is necessary, replace the filter assembly. 9694 Cover O‑ring seal Filter element Sight bowl INSTALLATION 1. Push the filter element into the cover. 2. Place the O‑ring seal into its proper position on the sight bowl and screw the sight bowl hand tight into the cover.
Page 86: Corrosion Control Anode
MAINTENANCE Assemble steering link rod to steering cable with flat washer and nylon insert locknut. Tighten locknut until it seats, then back nut off 1/4 turn. Assemble steering link rod to engine with bolt, locknut, spacer, and flat washers. Torque locknut to specifications. 9691 Bolt (10‑898101018) Flat washer (12‑95392‑10)
Page 87 MAINTENANCE Each anode requires periodic inspection, especially in salt water which will accelerate the erosion. To maintain this corrosion protection, always replace the anode before it is completely eroded. Never paint or apply a protective coating on the anode as this will reduce effectiveness of the anode.
Page 88: Spark Plug Inspection And Replacement
MAINTENANCE The second anode is on the water intake housing and the third anode is installed on the transom brackets. 10239 24838 Water intake housing anode Transom bracket anode Spark Plug Inspection And Replacement WARNING Avoid serious injury or death from fire or explosion caused by damaged spark plug boots.
Page 89: Fuse Replacement - Electric Start Models
MAINTENANCE 3. Set the spark plug gap to specifications. ob00680 Spark Plug Gap Spark plug 0.80‑0.90 mm (0.031‑0.035 in.) 4. Before installing spark plugs, clean off any dirt on the spark plug seats. Install plugs finger tight, and then tighten to the specified value.
Page 90: Timing Belt Inspection
Belt surfaces roughened. e. Signs of wear on edges or outer surfaces of belt. 9697 Lubrication Points 1. Lubricate the following with Quicksilver or Mercury Precision Lubricants Anti‑Corrosion Grease or 2‑4‑C with Teflon. Tube Ref No. Description Where Used Part No.
Page 91 Some discoloration of the grease is normal during the break‑in period on a new set of seals. 2. Lubricate the following with Quicksilver or Mercury Precision Lubricants 2‑4‑C with Teflon or Special Lubricant 101. Tube Ref No.
Page 92 MAINTENANCE • Swivel bracket ‑ Lubricate through fitting. 24839 • Tilt tube ‑ Lubricate through fittings. 15915 • Lubricate the threads on the transom clamp screws (if equipped). 15914...
Page 93 MAINTENANCE • Steering cable grease fitting (If equipped) ‑ Rotate the steering wheel to fully retract the steering cable end into the outboard tilt tube. Lubricate through fitting. 10161 Fitting Steering cable end WARNING The end of the steering cable must be fully retracted into the outboard tilt tube before adding lubricant.
Page 94: Checking Power Trim Fluid
2. Remove fill cap and check fluid level. The fluid level should be even with the bottom of the fill hole. Add Quicksilver or Mercury Precision Lubricants Power Trim & Steering Fluid. If not available, use automotive (ATF) automatic transmission fluid.
Page 95 MAINTENANCE OIL CHANGING PROCEDURE 1. Tilt the outboard up to the trailer position. 2. Turn the steering on the outboard so that the drain hole is facing downward. Remove the drain plug and drain engine oil into an appropriate container. Lubricate the seal on the drain plug with oil and reinstall.
Page 96: Submerged Outboard
MAINTENANCE OIL FILLING 1. Remove the oil fill cap and add oil to the proper operating level. 2. Idle the engine for five minutes and check for leaks. Stop the engine and check oil level on the dipstick. Add oil if necessary. 9737 Oil fill cap Submerged Outboard...
Page 97: Storage
STORAGE Storage Preparation The major consideration in preparing your outboard for storage is to protect it from rust, corrosion, and damage caused by freezing of trapped water. The following storage procedures should be followed to prepare your outboard for out of season storage or prolonged storage (two months or longer).
Page 98: Protecting Internal Engine Components
STORAGE • Spray Quicksilver or Mercury Precision Lubricants Corrosion Guard on external metal surfaces (except corrosion control anodes). Tube Ref No. Description Where Used Part No. External metal 92-802878-5 Corrosion Guard surfaces Protecting Internal Engine Components • Remove the spark plugs and inject a small amount of engine oil inside of each cylinder.
Page 99: Troubleshooting
TROUBLESHOOTING Starter Motor will not Crank the Engine (Electric Start Models) POSSIBLE CAUSES • Blown fuse in the starting circuit. Refer to Maintenance section. • Outboard is not shifted to neutral position. • Weak battery or battery connections are loose or corroded. •...
Page 100: Engine Runs Erratically
TROUBLESHOOTING • Spark plugs fouled or defective. Refer to Maintenance section. Engine Runs Erratically POSSIBLE CAUSES • Overheating ‑ Warning horn not working. • Low oil pressure. Check oil level. • Spark plugs fouled or defective. Refer to Maintenance section. •...
Page 101: Battery Will Not Hold Charge
TROUBLESHOOTING • Excessive water in bilge. • Boat bottom is dirty or damaged. Battery Will Not Hold Charge POSSIBLE CAUSES • Battery connections are loose or corroded. • Low electrolyte level in battery. • Worn out or inefficient battery. • Excessive use of electrical accessories.
Page 102: Owner Service Assistance
Refer to the Yellow Pages of the telephone directory. If, for any reason, you cannot obtain service, contact the nearest Mercury Marine Service Office. Parts And Accessories Inquiries All inquiries concerning genuine replacement parts and accessories should be directed to your local authorized dealer.
Page 103: Mercury Marine Service Offices
Model and serial number of your outboard • The name and address of your dealership • Nature of problem Mercury Marine Service Offices For assistance, call, fax, or write. Please include your daytime telephone number with mail and fax correspondence. United States Telephone (920) 929‑5040...
Page 104 OWNER SERVICE ASSISTANCE Japan Telephone 81‑053‑423‑2500 Mercury Marine - Japan Anshin-cho 283-1 Hamamatsu 81‑053‑423‑2510 Shizuoka-ken, Japan 435-0005 Japan Asia, Singapore Telephone 5466160 Mercury Marine Singapore 72 Loyang Way 5467789 Singapore, 508762...
Page 105: Engine Installation
ENGINE INSTALLATION Installation Information BOAT HORSEPOWER CAPACITY WARNING Using an outboard that exceeds the maximum horsepower limit of a boat can: 1) cause loss of boat control 2) place too much weight at the transom altering the designed flotation characteristics of the boat or 3) cause the boat to break apart particularly around the transom area.
Page 106: Top Cowl Removal And Installation
Some accessories not manufactured or sold by Mercury Marine are not designed to be safely used with your outboard or outboard operating system. Acquire and read the installation, operation, and maintenance manuals for all your selected accessories.
Page 107: Lifting Outboard
ENGINE INSTALLATION TOP COWL INSTALLATION 1. Engage the front hook and push the top cowl onto the lower cowl. 2. Push the cowl latch down to lock the cowl in place. Lifting Outboard Use the lifting eye located aft of the flywheel to support the engine when installing the outboard.
Page 108 ENGINE INSTALLATION BOATS WITH A "V" BOTTOM HULL 1. Measure the width of the leading edge on the water intake housing. Make a horizontal line on the transom up from the "V" bottom the same length as the width of the water intake housing.
Page 109: Fastening The Outboard
ENGINE INSTALLATION BOATS WITH A FLAT BOTTOM HULL 1. Place (center) the outboard on the boat transom. Set the height of the outboard on the boat transom so that the front edge of the water intake housing is in line with the bottom of the boat as shown.
Page 110: Steering Bracket, Steering Cable Installation
ENGINE INSTALLATION The outboard must be secured to the transom with the two transom bracket clamp screws and four 13 mm (1/2 in.) diameter mounting bolts and locknuts provided. Install two bolts through the upper set of mounting holes and two bolts through the lower set of mounting slots.
Page 111: Steering Link Rod Fasteners
ENGINE INSTALLATION 4. Install the steering cable and tighten the steering cable nut to the specified torque. 10268 Steering cable nut Cable seal Steering bracket bolt and washer (2) Description lb. in. lb. ft. Steering Cable Nut 47.5 Steering Bracket Bolt 22.13 Steering Link Rod Fasteners IMPORTANT: The steering link rod that connects the steering...
Page 112 ENGINE INSTALLATION Assemble steering link rod to engine with bolt, locknut, spacer, and flat washers. Torque locknut to specifications. 9691 Bolt (10‑898101018) Flat washer (12‑95392‑10) Spacer (23‑853826001) Nylon insert locknut (11‑16147‑‑3) Install steering link rod into side hole Nylon insert locknut (11‑16147‑‑3) (tighten until seats then back off 1/4 turn) Description lb.
Page 113: Electrical Harness, Battery Connection, Fuel Tanks
ENGINE INSTALLATION Electrical Harness, Battery Connection, Fuel Tanks REMOTE WIRING HARNESS 1. Remove the three access cover bolts. Remove the access cover and cable rubber grommet. 10113 2. Remove the cable barrel retainer. 24857 Cable barrel retainer...
Page 114 ENGINE INSTALLATION 3. Loosen the harness retainer. Route the remote harness into the cowl as shown and below the harness retainer. 24858 Harness retainer Remote harness 4. Connect the remote harness to the engine harness connector. 24859 Harness connector 5. Fasten the remote harness to the cowl with the harness retainer.
Page 115 ENGINE INSTALLATION BATTERY CABLE CONNECTIONS IMPORTANT: To prevent damage to the engine charging system when the battery cables are not connected to a battery, ensure the battery cable ends are thoroughly insulated. Single Outboard or86 Red sleeve ‑ positive (+) Cranking battery Black sleeve ‑...
Page 116 ENGINE INSTALLATION Dual Outboards Connect a common ground cable (wire size same as engine battery cables) between negative (–) terminals on starting batteries. or87 Red sleeve ‑ positive (+) Ground cable Black sleeve ‑ negative Cranking battery (–) FUEL TANKS Portable Fuel Tank Select a suitable location in the boat within the engine fuel line length limitations and secure the tank in place.
Page 117: Control Cable Installation
ENGINE INSTALLATION Control Cable Installation THROTTLE CABLE INSTALLATION Install the cables into the remote control following the instructions provided with the remote control. 1. Move the remote control handle from neutral into forward and advance the handle to full speed position. NOTE: The throttle cable is the second cable to move when moving the control box out of neutral.
Page 118 ENGINE INSTALLATION 6. Readjust the throttle cable barrel if the cam roller is touching the cam. 15952 Throttle cam Cam roller 7. Install the cable grommet. 8. Secure the throttle cable barrel with the cable barrel retainer. 9. Tighten the cable barrel retainer bolt to the specified torque. 24903 Cable barrel retainer Cable grommet...
Page 119 ENGINE INSTALLATION 10. Install the access cover and secure with three bolts. Tighten bolts to the specified torque. 15858 Description lb. in. lb. ft. Access cover bolt (3) SHIFT CABLE INSTALLATION WARNING The shift cable must be adjusted to lock the reverse gate against unexpected engagement (caused by water pressure) hitting the gate while operating the boat in forward.
Page 120 ENGINE INSTALLATION 4. Attach the shift cable adjustment barrel to the bracket with a bolt and locknut. Tighten the bolt until it seats against the adjustment barrel, then back‑off the bolt 1/4 turn. Hold the bolt from turning, and tighten the locknut on the bolt. The adjustment barrel must be free to pivot.
Page 121: Water Testing
ENGINE INSTALLATION Water Testing CHECKING FOR CAVITATION The initial outboard height setting should be close to the optimum setting for the outboard. However because of the hull design of some boats, obstructions, or imperfections in the hull ahead of the water intake, adjustments may be required to prevent cavitation at running speeds.
Page 122 ENGINE INSTALLATION 1. A rough water plate may be helpful in reducing cavitation when running in windy, rough water conditions where air is sucked into the water intake when jumping waves. Install a 0.8 mm (1/32 in.) metal plate that extends from the hull bottom to the top of the water intake housing.

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