Mercury 15 EFI FourStroke Service Manual
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Mercury 15 EFI FourStroke Service Manual

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15 / 20 EFI
FourStroke
SER VIC E
M A NU AL

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Questions and answers

Mitchell Disgdiertt
March 11, 2025

where do i put positive wires on motor 2021 Mercury 20 Hp 4 Stroke

-1
1 comments:
Mr. Anderson
March 11, 2025

The positive wires on a 2021 Mercury 20 HP FourStroke motor should be connected as follows:

- For models with power tilt: Connect the positive wire to the tilt-up relay.
- For models with electric start: Connect the positive battery cable to the starter solenoid.

This answer is automatically generated

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Summary of Contents for Mercury 15 EFI FourStroke

  • Page 1 15 / 20 EFI FourStroke SER VIC E M A NU AL...
  • Page 2 NOTE: Indicates information that helps in the understanding of a particular step or action. This manual has been written and published by the Mercury Marine Service Department to aid our dealers’ mechanics and company service personnel when servicing the products described herein. It is assumed that these personnel are familiar with marine product servicing procedures.
  • Page 3 Cleanliness and Care of Product A Mercury Marine power product is a combination of many machined, honed, polished, and lapped surfaces with tight tolerances. When any product component is serviced, care and cleanliness are important. Proper cleaning and protection of machined surfaces and friction areas is an implied part of the repair procedure.
  • Page 4 Color Diagrams 7 - Attachments A - Throttle and Shift Linkage B - Tiller Handle 8 - Manual Starter A - Recoil Starter 9 - Color Diagrams A - Color Diagrams Page iii © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 5 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page iv...

  • Page 6: Table Of Contents

    Ignition Specifications at 20 °C (68 °F)......1A-2 Oil System Specifications..........1A-5 Charging and Starting Specifications.........1A-3 Cooling System Specifications...........1A-6 Fuel System Specifications..........1A-3 Power Tilt Specifications............1A-6 Cylinder Block/Crankcase Specifications......1A-3 Gearcase Specifications............ 1A-6 Piston Specifications............1A-4 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1A-1...

  • Page 7: Model Specifications

    26.3 kPa (3.8 psi) Crankshaft position sensor 148–222 Ω Primary 0.26–0.35 Ω Ignition coil Secondary (with plug wires and caps) 16.8–20.2 kΩ Spark plug lead (without spark plug cap) 3.0–7.5 kΩ Page 1A-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 8: Charging And Starting Specifications

    Crankshaft main bearing oil clearance (service limit) 0.06 mm (0.002 in.) Crankshaft pin bearing oil clearance 0.015–0.041 mm (0.0006–0.0016 in.) Crankshaft pin bearing/connecting rod oil clearance (service limit) 0.060 mm (0.002 in.) 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1A-3...

  • Page 9: Piston Specifications

    Valve seat angles 30°, 45°, 60° Valve spring free length 32.85 mm (1.293 in.) Valve spring free length (service limit) 31.50 mm (1.240 in.) Valve spring tilt limit 1.1 mm (0.043 in.) Page 1A-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 10: Oil System Specifications

    Outer rotor height (service limit) 14.96 mm (0.589 in.) Rotor to oil pump cover clearance (service limit) 0.11 mm (0.004 in.) Inner rotor to outer rotor clearance (service limit) 0.13 mm (0.005 in.) 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1A-5...

  • Page 11: Cooling System Specifications

    460 ml (15.6 fl oz) Gear lubricant type Premium Gear Lubricant or GL5 SAE 80W‑90 Pinion teeth Pinion height Floating Clutch Dog type (forward–neutral–reverse) Forward, reverse teeth Forward gear backlash 0.8–1.5 mm (0.030–0.059 in.) Page 1A-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 12 Fuel Filter Replacement..........1B-5 Protecting Internal Engine Components....1B-18 Fuse Replacement ‑ Electric Start Models ......1B-7 Gearcase..............1B-18 Spark Plug Inspection and Replacement......1B-8 Positioning Outboard for Storage......1B-18 Timing Belt Inspection............1B-8 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1B-1...

  • Page 13: Cleaning Care

    Wax the surface using a nonabrasive automotive polish (polish designed for clear coat finishes). Remove the applied wax by hand using a clean soft cloth. To remove minor scratches, use Mercury Marine Cowl Finishing Compound (92‑859026K 1). Inspection and Maintenance Schedule Before Each Use Refer to the Owner's Manual for a list of checks and inspections that the owner should perform before each use.

  • Page 14: Every 300 Hours Of Use Or Three Years

    Before installing or removing a propeller, place the drive unit in neutral and engage the lanyard stop switch to prevent the engine from starting. Place a block of wood between the propeller blade and the anti‑ventilation plate. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1B-3...

  • Page 15: Fuel System

    Read Fuel System Precautions, preceding. Inspect the water‑separating fuel filter. If water is present, the red ring inside the filter assembly should float at the water level. Page 1B-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 16: Fuel Filter Replacement

    Pull the rubber mount downward, to remove it from the filter assembly. Remove the sight bowl from the filter housing. Filter housing Rubber mount Sight bowl 63111 Pull the filter element off the filter housing. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1B-5...
  • Page 17 Push the fuel filter element onto the filter housing. Verify the filter is completely installed by pushing on the filter in the locations shown in the following illustration. 63115 Install the sight bowl O‑ring seal onto the sight bowl and place the red ring into the sight bowl. Page 1B-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 18: Fuse Replacement - Electric Start Models

    Remove the fuse and examine the silver colored band inside the fuse. If the band is broken, replace the fuse. Replace the fuse with a new fuse of the same rating. Identifying an open fuse Good fuse Open (blown) fuse 28619 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1B-7...

  • Page 19: Spark Plug Inspection And Replacement

    Cracks in the back of the belt or in the base of the belt teeth • Excessive wear at the roots of the cogs • Rubber portion swollen by oil • Belt surfaces roughened Page 1B-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 20: Engine Oil

    NOTE: For models with kicker straps, temporarily disconnect one end of the port kicker strap. This will allow the engine to be rotated when the engine is in the full tilt position. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1B-9...

  • Page 21: Draining The Engine Oil

    Return the outboard to the full tilt position and drain the remaining oil. Page 1B-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 22: Filling The Crankcase With Oil

    Never paint or apply a protective coating to an anode, as this will reduce the effectiveness of the anode. The anodes are located as follows: 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1B-11...
  • Page 23 62960 62959 Power tilt model Manual tilt model When installing an anode, be certain to tighten the fasteners to the specified torque. Description lb‑in. lb‑ft Anode fasteners 53.1 – Page 1B-12 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 24: Propeller Replacement

    IMPORTANT: To prevent the propeller hub from corroding and seizing to the propeller shaft (especially in saltwater), always apply the recommended lubricant to the entire propeller shaft at the recommended maintenance intervals and also each time the propeller is removed. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1B-13...

  • Page 25: Installation

    Before installing or removing a propeller, place the drive unit in neutral and engage the lanyard stop switch to prevent the engine from starting. Place a block of wood between the propeller blade and the anti‑ventilation plate. Page 1B-14 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 26: Gearcase Lubricant Capacity

    Gearcase Lubricant Capacity Approximately 460 ml (15.6 fl oz). Gearcase Lubricant Recommendation Mercury or Quicksilver Premium or High Performance Gear Lubricant. Filling the Gearcase Place the outboard in a vertical operating position or in the full tilt position. Remove the vent plug from the vent hole.

  • Page 27: Lubrication Points

    Steering cable lubrication fitting (if equipped) ‑ Steer the outboard to fully retract the steering cable end into the outboard tilt tube. Lubricate the steering cable through the fitting. Steering cable lubrication fitting Steering cable end Tilt tube lubrication fittings 63286 Page 1B-16 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 28: Storage Preparation

    • Place the outboard in water or a water hose to the flush fitting for circulating cooling water. Run the engine for ten minutes to fill the engine fuel system. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1B-17...

  • Page 29: Protecting External Outboard Components

    Lubricate all outboard components listed in the Inspection and Maintenance Schedule, preceding. • Touch‑up any paint nicks. • Spray Quicksilver or Mercury Precision Lubricants Corrosion Guard on external metal surfaces (except corrosion control anodes). Tube Ref No. Description Where Used Part No.
  • Page 30 Storing the engine on the port side will prevent oil from draining out of the crankcase into the cylinders or crankcase ventilation system. There are bumpers on the aft side of the top cowl also. 63255 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1B-19...
  • Page 31 Maintenance Notes: Page 1B-20 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 32 Freshwater Submersion (Special Instructions)..1C-11 Shipping of Complete Engines and Major Assemblies Saltwater Submersion (Special Instructions)....1C-11 ................1C-17 Fuel Requirements............1C-11 More Information on Hazardous Material....1C-17 Low Permeation Fuel Hose Requirement ....1C-12 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1C-1...

  • Page 33: Recording Serial Number

    XXXXXXXX XXXX 62972 Serial number decal alpha code Model Year Manufactured Code Alpha Production Code Corresponding Number Examples: • XX = 2000 • HK = 2089 • AG = 2017 Page 1C-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 34: Engine Component Identification - Manual Start Model

    Engine harness 14‑pin connector Fuel line connector Shift lever Throttle control Stop (engine off) button Lanyard Throttle friction knob Copilot handle Tiller handle tilt lock lever Control cable from tiller handle 62790 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1C-3...

  • Page 35: 15/20 Fourstroke Efi Manual Start Starboard View

    Temperature and manifold absolute pressure (TMAP) sensor Idle air control (IAC) valve Throttle bypass (to IAC valve) Throttle link 14‑pin connector from operator controls Shift cable Copilot handle Tilt lock Page 1C-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 36: 15/20 Fourstroke Efi Manual Start Port View

    Crankshaft position sensor (CPS) Stator output wires Oil filter Thermostat housing Electrical bracket Spark plug (2) Cowl latch Spark plug wire (2) Fuel filter Ignition coil Oil pressure switch Flush connector 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1C-5...

  • Page 37: 15/20 Fourstroke Efi Manual Start Aft View

    Air intake Oil level dipstick Vent tank vent hose Vapor separator tank (VST) hoses Oil fill cap Fuel hose from low‑pressure fuel pump (behind driveshaft housing covers and cowl latch) 62793 Page 1C-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 38: Engine Component Identification - Electric Start Model

    Warning light Starter motor Recoil handle (for manual start) Recoil interlock cable Air box Engine harness 14‑pin connector Fuel line connector Power tilt pump wires Steering bracket 63008 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1C-7...

  • Page 39: 15/20 Fourstroke Efi Electric Start Starboard View

    NOTE: The TPS is behind (on the port side of) the throttle body. Temperature and manifold absolute pressure (TMAP) sensor Idle air control (IAC) Throttle bypass (to IAC) Throttle link (shown with throttle cable removed) Shift linkage (shown with shift cable removed) Page 1C-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 40: 15/20 Fourstroke Efi Electric Start Port View

    20‑amp fuse housing Voltage regulator/rectifier Spark plug (2) Fuel filter Spark plug wire (2) Ignition coil Oil pressure switch Cowl‑mounted tilt switch (RC power tilt models only) Engine flush connector 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1C-9...

  • Page 41: 15/20 Fourstroke Efi Electric Start Aft View

    (behind voltage regulator/rectifier wires) Engine lifting eye Air intake Oil level dipstick Vent tank vent hose Vapor separation tank (VST) hoses Oil fill cap Fuel hose from fuel pump (behind cowl) 63011 Page 1C-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 42: Following Complete Submersion

    Using Reformulated (Oxygenated) Gasoline (USA Only) Reformulated gasoline is required in certain areas of the USA and is acceptable for use in your Mercury Marine engine. The only oxygenate currently in use in the USA is alcohol (ethanol, methanol, or butanol).

  • Page 43: Low Permeation Fuel Hose Requirement

    Methanol and Ethanol Fuel Blends IMPORTANT: The fuel system components on your Mercury Marine engine will withstand up to 10% alcohol (methanol or ethanol) content in the gasoline. Your boat's fuel system may not be capable of withstanding the same percentage of alcohol.

  • Page 44: Gearcase And Lower Housing Refinishing

    Do not penetrate the primer. Wait no more than four days before topcoating. Topcoat with Stits Aerothane color code 215 for Mercury Phantom Black. Use Stits Catalyst U‑865 and UE‑820 Urethane Reducer per manufacturer's mixing and application directions. PPG Omni™ MTK9300 is an acceptable substitute. Apply two medium wet coats, allowing 15 minutes between.

  • Page 45: Emissions

    But carbon often combines with insufficient oxygen (one carbon atom with one oxygen atom). This forms carbon monoxide, CO. Carbon monoxide is the product of incomplete combustion and is a dangerous, potentially lethal gas. Page 1C-14 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 46: Emissions Information

    EPA Emission Regulations All new 1998 and newer outboards manufactured by Mercury Marine for operation in the USA, are certified to the United States Environmental Protection Agency as conforming to the requirements of the regulations for the control of air pollution from new outboard motors.

  • Page 47: Manufacturer's Certification Label

    Cut and remove a "V" notch through the month of engine manufacture before installing the new label. The month of manufacture can be found on the old label. If the label is missing or the date code illegible, contact Mercury Marine Technical Service for assistance.

  • Page 48: Shipping Of Hazardous Material (Hazmat) And Engine/Components Containing Hazardous Material

    More information on hazardous material, regulations, packaging, training, etc. can be found by going to the ShipMate website: http://www.shipmate.com or by calling: ShipMate Inc. Telephone + 1 (310) 370‑3600 + 1 (310) 370‑5700 E‑mail shipmate@shipmate.com 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1C-17...
  • Page 49 General Information Notes: Page 1C-18 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 50 Mounting Battery............1D-7 Steering Cable Installation..........1D-4 Battery Connections............1D-8 Steering Link Rod Fasteners..........1D-4 Connecting Outboard Battery Cables......1D-8 Remote Wiring Harness and Control Cable Installation..1D-5 Disconnecting Outboard Battery Cables....1D-8 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1D-1...

  • Page 51: Start In Gear Protection

    Failure to correctly fasten the outboard could result in the outboard propelling off the boat transom resulting in property damage, serious injury, or death. Before operation, the outboard must be correctly installed with the required mounting hardware. Page 1D-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 52 Power tilt models have four washers, manual tilt models have two washers Power tilt models have four nuts, manual tilt models have two nuts Description lb‑in. lb‑ft Transom bracket mounting bolts—all models 13.5 – 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1D-3...

  • Page 53: Steering Cable Installation

    Outboard Installation Steering Cable Installation Lubricate the entire cable end with Mercury or Quicksilver 2‑4‑C with PTFE. 28722 Tube Ref No. Description Where Used Part No. 2-4-C with PTFE Steering cable end 92-802859A 1 Insert the steering cable into the tilt tube.

  • Page 54: Remote Wiring Harness And Control Cable Installation

    Place a mark (b) on the cable next to the end guide. Make a center mark (c), midway between marks (a and b). Align the end guide with this center mark when installing the cable to the engine. 6098 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1D-5...

  • Page 55: Throttle Cable Installation

    Move the remote control handle from neutral into reverse and advance the handle to full speed position. Slowly return the handle back to neutral. Place a mark (b) on the cable next to the end guide. Page 1D-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 56: Battery Installation

    Electric starting outboards must have the battery cables connected to a battery whenever the engine is running, even if started manually, as damage to the charging system could result. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1D-7...

  • Page 57: Battery Connections

    Disconnecting Outboard Battery Cables First, disconnect the black battery cable from the (–) negative terminal and then disconnect the red battery cable from the (+) positive terminal. 27158 Page 1D-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 58 Warning Horn Location..........1E-5 Fault Codes..............1E-11 Warning Light Location..........1E-5 Mercury Universal Fault Codes........ 1E-11 Warning System Operation.........1E-5 Mercury Universal Fault Code Table (10/15/20)..1E-12 Engine Overheat............1E-6 Descriptive Fault List (10/15/20)....... 1E-13 Low Oil Pressure............1E-6 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine...

  • Page 59: Conditions Affecting Performance

    Common causes of cavitation are: • Weeds or other debris snagged on the propeller • Bent propeller blade • Raised burrs or sharp edges on the propeller Page 1E-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 60: Detonation

    The boat manufacturer and the selling dealer are responsible for equipping the power package with the correct propeller. Refer to Mercury Marine's web page https://www.mercurymarine.com/en/us/propellers/selector/#/step‑one. Select a propeller that will allow the engine power package to operate at or near the top end of the recommended WOT operating RPM range with a normal load.

  • Page 61: Compression Check

    Use the following table to aid in locating the source of cylinder leakage. Air Escaping From: Indicates Possible Defective: Throttle body Intake valve Exhaust system Exhaust valve Crankcase oil fill plug Piston or rings Adjacent cylinders Head gasket Page 1E-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 62: Guardian Protection System

    Warning System States The warning system, comprised of horn and light, serves to alert the operator to most engine system faults. There are two warning states: • Caution • Critical 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1E-5...

  • Page 63: Engine Overheat

    When the engine overspeed limiter is activated, the engine timing will be momentarily retarded to decrease the engine speed. Excessive overspeed will result in the momentary removal of ignition to prevent operation above the RPM limit. Page 1E-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 64: Wire Color Code Abbreviations

    About CDS G3 CDS G3 is a standalone program that provides diagnostic support for select Mercury engines and engine control systems. CDS G3 also supports all configuration functions necessary for preparing these systems for delivery. CDS G3 provides a clean, easy‑to‑navigate interface.

  • Page 65: Connecting Cds G3

    This manual assumes that you have successfully installed CDS G3 on your computer and have updated it to the most current version. For installation instructions, refer to the user manual loaded onto the computer diagnostic system laptop (in the Windows® Start menu > All Programs > Mercury Marine > User Manual). Connecting CDS G3...

  • Page 66: Cds G3 Screens (10/15/20 Efi)

    Injector pulse width Injector pulse width 64642 CDS G3 Live Data screen for 10/15/20 EFI FourStroke Units of measure are configurable, U.S. units shown Default temperature reading is 25 °C (77 °F) 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1E-9...

  • Page 67: Cds G3 Diagnostics Screen

    Use the Diagnostics screen to confirm proper operation of various system components. To perform one of the listed diagnostics, click the appropriate button, and follow the on‑screen instructions. Cylinder Misfire Fuel Pump Output Idle Air Control Horn Output LED Output Ignition Spark Injector Pulse 64646 Page 1E-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 68: Engine Control Module Pinout

    Mercury Universal Fault Codes Mercury universal fault codes help ensure uniformity in fault reporting in control modules. It also ensures that boat operators receive consistent information and instruction, such as Service Engine Soon, Reduce Engine Speed, and others in response to specific faults.

  • Page 69: Mercury Universal Fault Code Table (10/15/20)

    Mercury Universal Fault Code Table (10/15/20) Refer to the following table for an explanation of faults and possible solutions when using the CDS G3 diagnostic interface tool.

  • Page 70: Descriptive Fault List (10/15/20)

    300‑12 Wiring issue; bad component TPS short ‑ ground Caution None 300‑12 Wiring issue; bad component NOTE: *Refer to Warning System Operation for descriptions of the two types (states) of warnings. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 1E-13...
  • Page 71 General Troubleshooting Notes: Page 1E-14 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 72 ECM Systems Control Matrix........2A-4 Throttle Position Sensor (TPS)......... 2A-12 Troubleshooting............2A-4 Ignition Components............2A-13 Removal..............2A-4 Flywheel..............2A-13 Installation..............2A-4 Stator................ 2A-14 Wire Color Code Abbreviations..........2A-5 Timing Belt..............2A-16 Sensors................2A-5 Ignition Coil............... 2A-17 Crankshaft Position Sensor........2A-5 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2A-1...
  • Page 73 Ignition timing at idle 5° ± 5° BTDC Ignition timing at WOT 28° BTDC SeaPro models 5800 RPM RPM overspeed 15/20 JCI models 6300 RPM All other (10/15/20 hp) 6500 RPM Page 2A-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 74: Ignition Theory Of Operation

    CDS G3. An adapter harness connects the CDS G3 computer to the ECM diagnostic port. CDS G3 Diagnostic Tool Kit 8M0114141 CDS G3 Cable Kit 8M0137534 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2A-3...

  • Page 75: Ecm Systems Control Matrix

    For models with power tilt, connect the positive and negative wires to the tilt up relay. For models with electric start, connect the positive battery cable to the starter solenoid. Page 2A-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 76: Wire Color Code Abbreviations

    ECM to regulate ignition and fuel injector timing. If the CPS fails, the engine will run rough or stop running. Wiring Diagram ECM connector CPS connector RED/WHT RED/WHT RED/WHT 62903 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2A-5...
  • Page 77 Install the air box and recoil starter assembly. • It is easiest to install the recoil starter and air box together. • Refer to Section 8A ‑ Recoil Starter and Section 3C ‑ Air Box Installation. Page 2A-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 78: Engine Coolant Temperature (Ect) Sensor

    ECT sensor Flywheel Engine lifting eye 62969 ECT Sensor Test Place the ECT sensor in a container filled with water. Place a thermometer in the water, and slowly heat the water. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2A-7...
  • Page 79 Install the air box and recoil starter assembly. • It is easiest to install the recoil starter and air box together. • Refer to Section 8A ‑ Recoil Starter and Section 3C ‑ Air Box Installation. Page 2A-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 80: Oil Pressure Switch

    Oil filter 62970 Switch Testing Connect the red lead of an ohmmeter to the terminal and the black lead to the oil pressure switch metal body. DMT 2004 Digital Multimeter 91‑892647A01 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2A-9...

  • Page 81: Temperature And Manifold Absolute Pressure (Tmap) Sensor

    MAP is high when vacuum is low (such as at wide‑open throttle). The manifold air temperature (MAT) sensor measures the charge air temperature. This information is then conducted to the ECM for processing. 62990 Page 2A-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 82 Install the TMAP sensor into the throttle body, and tighten the retaining screws to the specified torque. Description lb‑in. lb‑ft TMAP retaining screws 26.6 – Connect the engine harness to the TMAP sensor. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2A-11...

  • Page 83: Throttle Position Sensor (Tps)

    Tighten the two Torx® screws. Confirm that the TPS value did not change. Disconnect CDS G3. Install the throttle body onto the engine. Refer to Section 3C ‑ Throttle Body Installation. Wiring Diagram RED/WHT RED/WHT BLU/WHT BLU/WHT BLK/BLU BLK/BLU 62912 Page 2A-12 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 84: Ignition Components

    Fasten a three‑point flywheel puller onto the flywheel. Do not use a jaw type puller. NOTE: Do not use heat or strike the flywheel. Loosen the flywheel using the puller. 63875 Remove the flywheel and retain the flywheel key. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2A-13...

  • Page 85: Stator

    The second winding generates the voltage required to maintain the battery on electric start models. This voltage is rectified external to the ECM. Refer to Section 2B ‑ Charging and Starting Systems. Page 2A-14 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 86 Remove the flywheel. Refer to Flywheel Removal. Electric start models: Disconnect the white and yellow stator wires (bullet connectors) from the voltage regulator/rectifier. Disconnect the blue and black/red stator wires (bullet connectors) from the engine harness. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2A-15...

  • Page 87: Timing Belt

    Remove the timing belt. NOTE: Use a flat‑blade screwdriver or similar tool to work the timing belt through the opening in the starter bracket. Be careful to not damage the belt. Page 2A-16 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 88: Ignition Coil

    NOTE: The readings listed were taken at 20 °C (68 °F) with a digital ohmmeter. Due to the number of different manufacturers, meters available, and temperature variance; test results may vary. It is not necessary to remove the ignition coil from the powerhead for testing. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2A-17...
  • Page 89 Remove the clips from the upper spark plug wire, and remove the spark plug wires from the spark plugs. NOTE: It is easiest to remove the wire and boot as a unit from the plug. Page 2A-18 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 90 Connect the orange and black coil input wires to the engine harness. Secure the wires to the harness and bracket with a cable tie. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2A-19...
  • Page 91 Ignition Notes: Page 2A-20 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 92 Testing the Stator Charge Windings......2B-9 Starter Motor Removal..........2B-14 Regulator/Rectifier Diode Test........2B-9 Starter Motor Disassembly........2B-14 Voltage Regulator/Rectifier Removal and Installation Starter Motor Reassembly........2B-15 ................2B-10 Starter Motor Installation...........2B-18 Starting System..............2B-11 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2B-1...

  • Page 93: Charging And Starting Specifications

    800 MCA, 650 CCA Voltage control Shunt/ground voltage regulator General Troubleshooting For general troubleshooting information, including connecting and using the CDS G3 diagnostic tool, refer to Section 1E ‑ General Troubleshooting. Page 2B-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 94 Charging and Starting Systems Notes: 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2B-3...

  • Page 95: Starter Motor Components

    Charging and Starting Systems Starter Motor Components 33809 Page 2B-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 96 Description lb‑in. lb‑ft Starter motor assembly Pinion assembly Washer Brush card Screw (M4 x 8) 13.3 – Bushing Screw 53.1 – Lockwasher Washer O‑ring Bushing Washer Lockwasher (M6) 35.4 – 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2B-5...

  • Page 97: Starter Motor And Solenoid Electrical Components

    Charging and Starting Systems Starter Motor and Solenoid Electrical Components 64407 Page 2B-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 98 Battery cable assembly Protective sleeve Screw 53.1 – Starter motor bracket Rubber mount Red terminal boot Protective sleeve Screw 53.1 – Starter motor – Neutral switch (tiller) – Start switch (tiller) 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2B-7...

  • Page 99: Wire Color Code Abbreviations

    If the battery accepts a satisfactory charge, determine the cause of the charging system problem as follows. • Check for correct battery polarity: red cable to positive (+) battery terminal. If polarity was incorrect, check for blown fuse and damaged rectifier. Refer to Regulator/Rectifier Diode Test. Page 2B-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 100: Testing The Stator Charge Windings

    Disconnect the yellow, white, and red voltage regulator/rectifier leads at the bullet connectors. Red wire Yellow wire White wire Bullet connectors Reusable cable tie Voltage regulator/rectifier 62981 Connect the meter leads to the appropriate voltage regulator/rectifier leads to perform the following tests. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2B-9...

  • Page 101: Voltage Regulator/Rectifier Removal And Installation

    – Attach the three bullet connectors for the red, yellow, and white wires, to complete the electrical connections. Secure the wires at the bullet connectors with the reusable cable tie. Page 2B-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 102: Starting System

    Check that the battery cables are connected to the correct polarity terminals: red (+), black (–) • Check cables and wiring for frayed and worn insulation. • Check the in‑line fuse. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2B-11...

  • Page 103: Starting System Wiring Diagrams

    Starter motor Starter solenoid (disconnect at TP2 for tests 2 through 6) Battery 15‑amp fuse Chassis ground Engine harness 14‑pin connector Remote control harness 14‑pin connector Key switch Neutral start switch Page 2B-12 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 104: Starting System Troubleshooting Chart

    Starter Motor Current Draw IMPORTANT: The starter motor current draw test must be performed with a fully charged battery. Condition Current Draw No load test 13 A Normal operation (cranking) 45–50 A 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2B-13...

  • Page 105: Starter Motor Removal

    Bendix 10500 Remove two bolts on the bottom of the starter holding it together. 10502 Remove the top end cap. Do not lose any armature shims. Remove the field frame. Page 2B-14 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 106: Starter Motor Reassembly

    Insert the power stud through the end cap. Install the two brush card screws. Do not tighten the brush card screws. Power stud Power stud insulator Brush card screw (2) 10505 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2B-15...
  • Page 107 Push the brush in and insert a 2.6 mm (0.093 in.) drill bit between the brush spring and the brush card. This will hold the spring and brush for the insertion of the armature into the end cap. Page 2B-16 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 108 10539 Tube Ref No. Description Where Used Part No. SAE® Engine Oil 30W Armature shaft Obtain Locally 15. Ensure the lockwasher and washer are installed onto the starter assembly screws. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2B-17...

  • Page 109: Starter Motor Installation

    Attach the positive cable to the starter motor, using a lockwasher and nut. Tighten the nut to the specified torque. Attach the negative cable to the starter motor, using a lockwasher and nut. Tighten the nut to the specified torque. Page 2B-18 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 110 It is easiest to install the recoil starter and air box together. • Refer to Section 8A ‑ Recoil Starter and Section 3C ‑ Air Box Installation. Connect the battery cables to the battery, positive connection first. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 2B-19...
  • Page 111 Charging and Starting Systems Notes: Page 2B-20 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 112 Throttle Position Sensor (TPS)........3A-4 Engine Control Module (ECM)........... 3A-3 Actuators................3A-4 Overview..............3A-3 Function of Actuators..........3A-4 ECM and Fuel Injection..........3A-3 Idle Air Control (IAC)...........3A-4 Troubleshooting............3A-4 Fuel Injector..............3A-5 Additional Information..........3A-4 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3A-1...

  • Page 113: Theory Of Operation

    The high‑pressure fuel pump is pulse‑width modulated by the ECM to deliver fuel flow in excess of the fuel volume injected in the intake manifold by the fuel injectors. The excess fuel recirculates through the pressure relief valve within the VST. Page 3A-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 114: Throttle Body

    Idle air control: Stabilizes the engine RPM when idling and during quick engine RPM deceleration by managing the duty cycle driving the IAC in order to control bypass air entering the intake manifold 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3A-3...

  • Page 115: Troubleshooting

    Provides additional intake air for the engine during start‑up, and allows increased idle RPM during engine warm‑up. • Controls idle speed according to the varying engine loads and running conditions. Page 3A-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 116: Fuel Injector

    An injector filter screen is located on the fuel inlet side of the injector. The filter screen is not replaceable, but can be cleaned of debris. 21100 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3A-5...
  • Page 117 Fuel System Operation Notes: Page 3A-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 118 Section 3B - Troubleshooting and Diagnostics Table of Contents General Troubleshooting........... 3B-2 Wire Color Code Abbreviations..........3B-3 Testing Fuel System Inlet Vacuum........3B-2 Fuel System Wiring Diagram..........3B-3 Fuel Pressure Test.............3B-2 Sensor Wiring Diagram............3B-4 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3B-1...

  • Page 119: General Troubleshooting

    Clear fuel line T‑fitting Boat fuel line 4439 Fuel System Inlet Vacuum Maximum 8.5 kPa (2.5 in. Hg) Fuel Pressure Test Install a fuel pressure gauge onto the fuel rail service port. Page 3B-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 120: Wire Color Code Abbreviations

    GRN/RED LT GRN/BLK GRN/RED BLK/WHT BLK/YEL BLK/GRN 63056 15/20 EFI fuel system wiring diagram Engine control module Fuel injector #1 Fuel injector #2 Idle air control valve High‑pressure fuel pump 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3B-3...

  • Page 121: Sensor Wiring Diagram

    Throttle position sensor (TPS) Engine coolant temperature (ECT) 1 2 3 4 1 2 3 sensor Crankshaft position sensor (CPS) Engine control module (ECM) GRN/ORN RED/WHT RED/WHT BLU/WHT GRN/YEL GRN/WHT BLK/BLU 63750 Page 3B-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 122 Air Box Installation............3C-23 Fuel Cooler............... 3C-15 Idle Air Control (IAC)............3C-24 VST Installation............3C-16 IAC Removal............3C-24 Camshaft Gear Cover/Vent Tank........3C-17 IAC Test..............3C-24 Removal..............3C-17 IAC Installation............3C-25 Installation..............3C-18 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3C-1...

  • Page 123: Fuel System Specifications

    Electric high pressure Fuel pump pressure (mechanical) 30 kPa ± 20 kPa (4.3 psi ± 2.9 psi) Fuel pump pressure (electric) 256 kPa ± 25 kPa (37.1 psi ± 3.6 kPa) Page 3C-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 124 Service Procedures Notes: 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3C-3...

  • Page 125: Fuel System Components

    Service Procedures Fuel System Components 64410 Page 3C-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 126 Fuel hose Screw with washer 53.1 – Fuel pump assembly O‑ring Clamp Hose clamp Fuel hose Fuel filter assembly Fuel filter holder Bracket Screw 53.1 – Hose clamp Clamp Fuel hose 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3C-5...

  • Page 127: Vapor Separator Tank Components

    Service Procedures Vapor Separator Tank Components 64412 Page 3C-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 128 Fuel regulator Holder Screw 17.7 – Float valve assembly Float arm pin Float O‑ring Fuel pump Filter holder Filter Grommet VST lower housing Drain screw Seal Cover Screw 17.7 – 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3C-7...

  • Page 129: Air Intake Components

    Service Procedures Air Intake Components 64529 Page 3C-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 130 Throttle body assembly Idle air control valve Screw 26.6 – Screw 26.6 – TMAP sensor Gasket Restrictor (10/15 hp models only) Gasket Rubber mount Collar Breather hose Hose clamp 53.1 – Washer 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3C-9...

  • Page 131: Fuel Lift Pump

    Secure the fuel pump assembly to the cylinder head cover with two screws. Tighten the screws to the specified torque. Fuel pump screws (2) Fuel out hose Fuel in hose 62995 Description lb‑in. lb‑ft Fuel pump screws (2) 53.1 – Page 3C-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 132: Vapor Separator Tank (Vst)

    Using an appropriate container to capture the fuel, open the VST drain screw and allow the VST to drain completely. Disconnect the high‑pressure fuel pump wire harness connector. Remove the two screws securing the VST to the cylinder block, and pull the assembly away from the engine. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3C-11...
  • Page 133 11. Pull the entire assembly away from the engine, carefully pulling the two fuel cooler water hoses through the holes in the midplate. VST vent hoses Fuel cooler water supply hose Fuel cooler drain hose (water pump indicator hose) High‑pressure fuel hose (to fuel rail) 62926 Page 3C-12 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 134: Vst Disassembly

    White fuel pump wire 63132 Remove the check valve and O‑ring. Remove the clip that secures the fuel pump electrical connector, and remove the connector and O‑ring from the cover. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3C-13...

  • Page 135: Vst Reassembly

    Ensure that the fuel pump wires route outside of the screw boss, and secure the check valve with the clamp and screw. Attach the white, yellow, and red wires to the fuel pump. Page 3C-14 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 136: Fuel Cooler

    Assemble the two halves of the VST assembly, and secure with four screws. Fuel Cooler To remove the cover on the VST's fuel cooler chamber: Remove four screws and remove the fuel cooler cover. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3C-15...

  • Page 137: Vst Installation

    Connect the high‑pressure fuel hose to the VST with a new Oetiker® clamp. Clamp Tool 91‑803146T VST vent hoses Fuel cooler water supply hose Fuel cooler drain hose (water pump indicator hose) High‑pressure fuel hose (to fuel rail) 62926 Page 3C-16 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 138: Camshaft Gear Cover/Vent Tank

    Air Box and Section 8A ‑ Recoil Starter . Removal Remove the vent hose from the cover assembly. Remove the two vapor separator (VST) tank hoses from the cover assembly. Remove the crankcase breather hose. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3C-17...

  • Page 139: Installation

    Remove the temperature and manifold absolute pressure (TMAP) sensor. Refer to Section 2A ‑ Temperature and Manifold Absolute Pressure (TMAP) Sensor. Air box Recoil starter assembly IAC valve harness connector Throttle link TPS harness connector TMAP sensor 63035 Page 3C-18 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 140: Throttle Body Installation

    Connect the throttle position sensor (TPS) to the engine harness. Install the recoil starter and air box. • It is easiest to install the recoil starter and air box together. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3C-19...

  • Page 141: Fuel Rail

    Remove the two screws securing the fuel rail to the intake manifold. Do not lose the clamp securing the fuel rail to the intake manifold. Pull the fuel rail assembly off the intake manifold. Remove the Oetiker® clamp securing the fuel hose to the fuel rail inlet tube. Page 3C-20 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 142: Fuel Rail Disassembly

    Install new O‑rings onto the fuel inlet tube. O‑rings (2) 11643 Lubricate the fuel inlet tube O‑rings with clean engine oil. Install the fuel inlet tube onto the fuel rail. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3C-21...

  • Page 143: Fuel Rail Installation

    Ensure that the spacer is in place, and secure the fuel rail to the intake manifold with two screws. Tighten the screws to the specified torque. Description lb–in. lb–ft Fuel rail screw 53.1 – Crimp the Oetiker® clamp to secure the fuel hose. Clamp Tool 91‑803146T Page 3C-22 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 144: Air Box

    Secure the air box to the engine with three screws. Tighten the screws to the specified torque. Description lb‑in. lb‑ft Air box screws (3) 53.1 – Attach the crankcase ventilation hose to the valve cover, and secure it with the spring clamp. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3C-23...

  • Page 145: Idle Air Control (Iac)

    If the vacuum is not released when 12 volts is applied to the IAC terminals, replace the IAC. 12 volts positive 12 volts negative 22595 Connect the DMT 2004 Digital Multimeter tool to the terminal pins of the IAC. 23017 Page 3C-24 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 146: Iac Installation

    Be certain to attach the crankcase breather hose and the bypass hose to the air box. • Install the recoil starter assembly before tightening the top air box mounting screw. IAC mounting screws (2) Bypass hose Engine harness connector 62992 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 3C-25...
  • Page 147 Service Procedures Notes: Page 3C-26 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 148 Thermostat, Exhaust Cover, and Anode Installation Powerhead Cleaning, Inspection, and Repair....4A-16 ................4A-28 Flywheel..............4A-16 Oil Strainer Installation..........4A-30 Crankshaft Timing Gear..........4A-17 Throttle Body Installation.......... 4A-30 Timing Belt..............4A-17 Electrical Component Installation......4A-31 Anode............... 4A-17 Powerhead Installation.............4A-33 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-1...

  • Page 149: Cylinder Block/Crankcase Specifications

    Crankshaft pin bearing/connecting rod oil clearance (service limit) 0.060 mm (0.002 in.) Connecting rod wrist pin bore diameter 16.010–16.021 mm (0.6303–0.6307 in.) Connecting rod wrist pin bore diameter (service limit) 16.025 mm (0.6309 in.) Page 4A-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 150: Piston Specifications

    0.5 mm (0.02 in.) Second ring end gap 0.35–0.50 mm (0.0138–0.0197 in.) Second ring end gap (service limit) 0.7 mm (0.028 in.) Oil ring end gap 0.2–0.7 mm (0.008–0.028 in.) 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-3...

  • Page 151: Cylinder Block And Crankcase Components

    Cylinder Block/Crankcase Cylinder Block and Crankcase Components 64413 Page 4A-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 152 Oil pan gasket First 15.0 132.7 – Screw (M8 x 35) Final 30.0 – 22.1 Oil strainer Cable tie Hose Cowl standoff 53.1 – Cowl standoff 53.1 – Rubber cowl support 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-5...

  • Page 153: Crankshaft Components

    Cylinder Block/Crankcase Crankshaft Components 64577 Page 4A-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 154 Plain shaft bearing, red (set of 2) Upper oil seal Lower oil seal Piston assembly Piston Piston pin Piston pin clip Piston ring kit Top piston ring Second piston ring Oil ring 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-7...

  • Page 155: Powerhead Removal

    Disconnect the crankshaft position sensor (CPS) from the engine harness. Remove the screw and washer that holds the 14‑pin connector to the stator/starter bracket. Remove the two screws and washers that connect the ground terminals to the stator/starter bracket. Page 4A-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 156 Cable tie Fuel inlet hose Fuel filter Fuel filter outlet hose 63877 Remove one screw to remove the fuel filter bracket. Remove the fuel hoses from the fuel pump. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-9...

  • Page 157: Cylinder Block Disassembly

    Remove the ignition coil. Refer to Section 2A ‑ Ignition Coil. Disconnect the red bullet connector for the voltage regulator/rectifier (electric start models) and the 2‑pin connector for the ECT sensor. Page 4A-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 158 Power tilt pink and light blue bullet connectors Oil pressure switch, rubber boot and ring terminal removed 63940 11. Remove the ECM from its bracket, and remove two screws to remove the bracket from the engine. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-11...

  • Page 159: Throttle Body Removal

    Remove one screw to remove the dipstick extension tube. Dipstick extension tube screw Throttle body nuts 63943 Crankshaft Timing Gear Removal Flatten the turned‑up segment of the lockwasher. Remove the crankshaft timing gear nut. Page 4A-12 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 160: Thermostat And Exhaust Cover Removal

    Oil pressure switch 63992 Remove the cylinder head assembly. Refer to Section 4B ‑ Cylinder Head Removal. Inspect the water cooling passages in the block and the exhaust cover for debris. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-13...

  • Page 161: Oil Strainer Removal

    Identify the connecting rod and cap position with indelible ink or paint. Do not use a scribe or punch for identification. IMPORTANT: Each connecting rod and cap are a matched set. Do not intermix the connecting rod caps with the connecting rods. Remove the crankshaft. Page 4A-14 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 162 Install the connecting rod caps onto their respective connecting rods. Tighten the connecting rod cap screws finger‑tight. Piston and connecting rod Connecting rod cap Cap screws 64147 Push the connecting rod assembly out of the cylinder block. 64148 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-15...

  • Page 163: Piston Disassembly

    Piston pin Piston pin clip (2) 64150 Piston Ring Expander 91‑ 24697 Powerhead Cleaning, Inspection, and Repair Flywheel Inspect the flywheel keyway and teeth. Replace if damaged or worn. 3116 Page 4A-16 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 164: Crankshaft Timing Gear

    Out of round (service limit) 0.06 mm (0.0023 in.) Taper (service limit) 0.08 mm (0.0032 in.) Piston Measurements Inspect piston wall for wear or damage. Replace the piston if necessary. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-17...
  • Page 165 Oil "c" (service limit) 0.15 mm (0.0059 in.) Piston Ring End Gap Measure the piston ring end gap clearance. Replace the piston rings as a set if out of specification. Page 4A-18 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 166: Connecting Rod Measurements

    Connecting rod cap bolts 10.0 88.5 – Measure the small (piston pin) and large (crankshaft pin journal) ends of the connecting rod. Crankshaft pin journal end Piston pin end 22418 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-19...

  • Page 167: Crankshaft

    IMPORTANT: Use new main bearings, do not reuse the removed main bearings. Ensure that the mating surfaces on the crankcase cover and cylinder block are clear of debris. Clean all the oil from the following areas: Page 4A-20 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 168 10.0 88.5 – First Main bearing bolts (1–4) (M8 x 50) 23.5 – 17.3 Final 53.1 – First Crankcase cover bolts (5–10) (M6 x 30) 11.5 101.8 – Final 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-21...
  • Page 169 3147 Bearing Code Bearing Color Bearing Size Bearing Thickness A, X Blue 39.0–39.008 mm (1.5354–1.5357 in.) 1.488–1.494 mm (0.0586–0.0588 in.) B, Y 39.008–39.016 mm (1.5357–1.5361 in.) 1.494–1.500 mm 0.0588–0.0591 in.) Page 4A-22 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 170: Connecting Rod Oil Clearance

    Measure the gauging plastic at its maximum compressed width. Compressed gauging plastic Gauging plastic scale 11650 Connecting Rod Oil clearance 0.015–0.041 mm (0.0006–0.0016 in.) Service limit 0.060 mm (0.002 in.) 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-23...

  • Page 171: Powerhead Assembly

    Use a piston ring expander to install the oil ring, second ring, and top ring. IMPORTANT: The "T" on the first and second ring must face the crown of the piston. Piston Ring Expander 91‑ 24697 Page 4A-24 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 172: Piston Installation

    Using the piston ring compressor tool, install the piston/connecting rod assembly into the cylinder block. Push down on the piston compressor tool to ensure that the tool is firmly seated against the block. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-25...

  • Page 173: Crankshaft Installation

    NOTE: Refer to the Crankshaft Components assembly view for correct installation direction of the crankshaft seals. 64153 Main bearings Connecting rod Lower crankshaft seal Main bearing journal Connecting rod journal Upper crankshaft seal Page 4A-26 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 174 Description Where Used Part No. Loctite® Master Gasket Cylinder block and crankcase cover mating surfaces 92-12564 2 13. Lubricate the main bearing and crankcase cover bolts with clean engine oil. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-27...

  • Page 175: Crankshaft Timing Gear Installation

    NOTE: Install the spark plugs as directed, but do not install the throttle body or removed electrical components at this time. Install a new exhaust cover gasket. Install the exhaust cover, and start but do not tighten the five M6 x 25 screws. Page 4A-28 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 176 Apply Loctite® 567 PST Pipe Sealant to the oil pressure switch threads. Install the oil pressure switch, and tighten it to the specified torque. Tube Ref No. Description Where Used Part No. Loctite® 567 PST Pipe Oil pressure switch threads 92-809822 Sealant 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-29...

  • Page 177: Oil Strainer Installation

    Ensure that an O‑ring is on the dipstick tube extension. Lubricate the O‑ring with clean engine oil. Install the dipstick extension tube, and secure it with a single screw and washer. Tighten the screw to the specified torque. Install a gasket onto the throttle body studs. Page 4A-30 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 178: Electrical Component Installation

    Voltage regulator/rectifier bracket screws 53.1 – Power tilt models: Install the tilt relay/start solenoid bracket onto the engine, using two screws. Tighten the screws to the specified torque. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-31...
  • Page 179 10. Slide the yellow fuse housing onto the thermostat cover electrical bracket. 11. Connect the engine harness 2‑pin connector to the engine coolant temperature (ECT) sensor. Page 4A-32 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 180: Powerhead Installation

    Ensure that the powerhead gasket, driveshaft seal, and rubber seal are in place on the driveshaft housing. Refer to Section 5A ‑ Driveshaft Housing Installation for details. Install the powerhead onto the driveshaft and driveshaft housing. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-33...
  • Page 181 Connect the fuel filter outlet hose to the fuel filter. Secure the connection with a hose clamp, and secure the hose to the upper spark plug lead with a clip, as shown. Page 4A-34 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 182 Connect the crankshaft position sensor (CPS) to the engine harness. CPS connector Screw and washer for the 14‑pin connector bracket Screws and washers for ground terminals (2 each) Screw and washer securing relay bracket to stator/starter bracket 63936 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-35...
  • Page 183 Install the driveshaft housing covers. Refer to Section 5A ‑ Driveshaft Housing Covers. 10. Add 10W‑30 4‑Stroke Marine Engine Oil to the crankcase to the recommended fluid level. Refer to Section 1B ‑ Filling the Crankcase with Oil. Page 4A-36 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 184 Cylinder Block/Crankcase Tube Ref No. Description Where Used Part No. 10W-30 4-Stroke Marine Engine crankcase 92-8M0078625 Engine Oil 11. For electric start models, connect the battery cables to the battery. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4A-37...
  • Page 185 Cylinder Block/Crankcase Notes: Page 4A-38 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 186 Rocker Arm and Rocker Arm Shaft Inspection..4B-17 Cylinder Head Removal........... 4B-11 Valve Seat Reconditioning........4B-17 Cylinder Head Disassembly..........4B-13 Cylinder Head Assembly..........4B-19 Cleaning and Inspection..........4B-15 Cylinder Head Installation..........4B-21 Camshaft..............4B-15 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4B-1...

  • Page 187: Cylinder Head Specifications

    5.48 mm (0.216 in.) Intake (service limit) 5.46 mm (0.215 in.) Valve stem diameter Exhaust 5.46 mm (0.215 in.) Exhaust (service limit) 5.44 mm (0.214 in.) Cylindricity (maximum) 0.01 mm (0.0004 in.) Page 4B-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 188 (0.00023–0.0014 in.) 17.975–17.990 mm Cylinder head upper camshaft bearing inside diameter (0.7077–0.7083 in.) 15.965–15.980 mm Oil pump camshaft bearing inside diameter (0.6285–0.6291 in.) Intake Black Valve stem seal color Exhaust Green 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4B-3...

  • Page 189: Cylinder Head Components

    Cylinder Head Cylinder Head Components 64414 Page 4B-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 190 – Spark plug 18.0 159.3 – Cylinder head cover gasket Screw 13.3 – Breather chamber cover Cylinder head cover Screw (M6 x 30) 53.1 – Oil filler cap O‑ring Nipple 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4B-5...

  • Page 191: Intake/Exhaust Valve Components

    Cylinder Head Intake/Exhaust Valve Components 64539 Page 4B-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 192 Intake valve stem seal Valve spring seat Valve spring Retainer Keeper Adjusting screw Rocker arm Locknut – Collar Exhaust valve Exhaust valve stem seal Rocker shaft spring Washer Rocker arm shaft 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4B-7...

  • Page 193: Camshaft And Oil Pump Components

    Cylinder Head Camshaft and Oil Pump Components 64415 Page 4B-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 194 – 47.2 Timing belt Screw (M6 x 20) 11.5 101.8 – Washer Driven gear Oil seal Camshaft assembly Oil pump gasket Oil pump assembly Screw (M6 x 35) 53.1 – 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4B-9...

  • Page 195: Valve Adjustments

    Square drive socket Wrench Locknut Adjusting screw 64134 Valve Clearance (Cold) Intake 0.13–0.17 mm (0.005–0.007 in.) Exhaust 0.18–0.22 mm (0.007–0.008 in.) Perform the following adjustment steps if out of specification: Page 4B-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 196: Cylinder Head Removal

    Remove the throttle body from the cylinder head. Refer to Section 4A ‑ Throttle Body Removal. Remove the three screws holding the oil pump to the cylinder head. Underside of cylinder head Screws (3) 64017 Remove the camshaft gear retaining screw. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4B-11...
  • Page 197 Cylinder head retaining screw (M8 x 60) (6) Perimeter screw (M6 x 40) and washer (1) Perimeter screw (M6 x 25) and washer (2) 64033 12. Remove the cylinder head. Page 4B-12 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 198: Cylinder Head Disassembly

    Rocker arm (4) Spacer (2) 64121 Lock‑Ring Pliers Snap‑On SRP‑4 Remove the camshaft. Be careful to not damage the decompression valves. Decompression valves (2) Remove the camshaft from the cylinder head 64122 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4B-13...
  • Page 199 Remove keepers, upper seats, springs, seals, lower seats, and intake/exhaust valves. NOTE: Valve seals are not reusable. Exhaust valve Intake valve Valve seat Valve seal Valve spring Retainer Keepers 3200 Page 4B-14 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 200: Cleaning And Inspection

    Measure the valve stem cylindricity. Replace the valves if out of specification. 20970 Cylindricity (Maximum) Intake and exhaust 0.01 mm (0.0004 in.) Measure the valve stem outer diameter. Replace valves if out of specification. 20971 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4B-15...

  • Page 201: Valve Springs

    Apply a light downward pressure on the head. Move the head in the pattern shown. Rotate the head several times during the resurfacing procedure to avoid removing material from one side. Page 4B-16 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 202: Valve Guides

    Correct valve seat contact width Valve seat too high Valve seat too low 20969 Valve seat too wide Valve Seat Contact Width Intake and exhaust valve 1.0–2.0 mm (0.0393–0.0787 in.) 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4B-17...
  • Page 203 10. If the valve seat contact area is too wide and situated in the center of the valve face, use the 30° cutting tool to cut the top edge of the valve seat and the 60° cutting tool to cut the bottom edge of the valve seat, to adjust its contact width. Previous contact width 20979 Page 4B-18 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 204: Cylinder Head Assembly

    Description Where Used Part No. 4-Stroke 10W-30 Valve stems 92-8M0078625 Outboard Oil NOTE: The green valve seal is for the exhaust and the black valve seal is for the intake. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4B-19...
  • Page 205 64128 Lubricate the rocker shaft components and the camshaft lobes with 4‑Stroke 10W‑30 Outboard Oil. Install the rocker shaft, washers, rocker arm shaft, spacer, springs, and rocker arms, as shown. Page 4B-20 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 206: Cylinder Head Installation

    IMPORTANT: Cylinder head screws must be tightened in two steps and in the sequence shown. Tighten the cylinder head screws and the perimeter screw to the specified torque in sequence in two steps. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4B-21...
  • Page 207 Camshaft gear screw threads 92-809818 Threadlocker Description lb‑in. lb‑ft Camshaft gear screw (M6 x 20) 11.5 101.8 – 10. Install the oil pump. Refer to Section 4C ‑ Oil Pump Installation. Page 4B-22 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 208 14. Install the gasket into the groove of the cylinder head cover. 64078 15. Install the four cylinder head cover screws. Tighten the screws to the specified torque. Screw (M6 x 30) (4) Cylinder head cover 64032 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4B-23...
  • Page 209 Electrical components removed from the cylinder head (refer to Section 4A ‑ Electrical Component Installation) 18. Install the powerhead onto the driveshaft housing. Refer to Section 4A ‑ Powerhead Installation. Page 4B-24 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 210 Section 4C - Oil Pump Table of Contents Oil System Specifications..........4C-2 Oil Pump Assembly............4C-3 Oil Pump Removal.............4C-2 Oil Pump Installation............4C-4 Oil Pump Disassembly............4C-2 Oil Flow Diagram............... 4C-6 Oil Pump Inspection............4C-3 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4C-1...
  • Page 211 IMPORTANT: The pressure relief spring presses against the oil pump housing cover. Exercise care to not lose the spring, when removing the cover. Remove the two screws securing the cover to the oil pump housing. Remove the cover. 64055 Page 4C-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 212 Install the inner rotor into the oil pump housing with the keyway facing towards the cover. Install the drive pin into the shaft. Install the shaft with the drive pin into the inner rotor. Ensure the drive pin engages with the inner rotor keyway. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4C-3...
  • Page 213 Place a new gasket on the oil pump. Align the camshaft roll pin and the slot in the pump shaft. Camshaft roll pin Slot in pump shaft Oil pump gasket 64073 Page 4C-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 214 Fasten the oil pump to the cylinder head with three M6 x 35 screws. Tighten the screws to the specified torque. Cylinder head Screw (M6 x 35) 64017 Description lb‑in. lb‑ft Oil pump mounting screws 53.1 – 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4C-5...
  • Page 215 Hose Pump Camshaft journal Regulator valve Filter Main gallery Oil pressure switch Camshaft faces Rocker arm shaft and valve Crankshaft main bearing Crankshaft rod journal Cylinder wall Piston Piston pin Page 4C-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 216 Section 4D - Cooling System Table of Contents Cooling System Specifications.......... 4D-2 Thermostat/Electrical Bracket Removal..... 4D-2 Cooling System Description..........4D-2 Testing the Thermostat..........4D-2 General Troubleshooting........... 4D-2 Thermostat/Electrical Bracket Installation....4D-3 Thermostat.................4D-2 Water Flow Diagram............4D-4 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4D-1...
  • Page 217 Suspend the thermostat in cold water. Suspend a thermometer in the water. IMPORTANT: Do not allow the thermometer to contact the heating surface of the container. An inaccurate temperature reading may result. Page 4D-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 218 Secure the wires to the upper end of the electrical bracket with the reusable cable tie. Lower cable tie (new) Screw (2) Thermostat housing with new gasket Reusable cable tie Fuse housing Electrical bracket 63057 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4D-3...
  • Page 219 Cooling System Water Flow Diagram Water inlet Water pump Water tube Cylinder block Thermostat Cylinder head Fuel cooler (part of the vapor separator tank) Water pump indicator outlet 64794 Page 4D-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 220 Installation..............5A-22 Shift Operation..............5A-48 Engine Mount Replacement..........5A-23 Kicker Strap (Tiller Handle Model)........5A-48 Upper Mount............. 5A-23 Removal..............5A-49 Lower Mount............. 5A-23 Installation..............5A-49 Clamp Brackets, Swivel Bracket ‑ Power Tilt Models..5A-25 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-1...
  • Page 221 92-809818 Loctite® 242 Threadlocker Idle exhaust port cover screws 92-809821 Tilt tube washer Swivel bracket bushings 2-4-C with PTFE Tilt pin and bushings 92-802859A 1 Tilt tube Steering arm O-ring Page 5A-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 222 Clamp/Swivel Bracket and Driveshaft Housing Notes: 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-3...

  • Page 223: Clamp Bracket Components (Power Tilt)

    Clamp/Swivel Bracket and Driveshaft Housing Clamp Bracket Components (Power Tilt) 20 21 63491 Page 5A-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 224 13.5 – Washer Transom screw Stepped collar (ProKicker models) Strap (ProKicker models) Screw (M6 x 25) (ProKicker models) 53.1 – Washer (ProKicker models) Collar (ProKicker models) Large washer (ProKicker models) 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-5...

  • Page 225: Clamp Bracket Components (Manual Tilt)

    Clamp/Swivel Bracket and Driveshaft Housing Clamp Bracket Components (Manual Tilt) 48 49 47 48 27 28 63293 Page 5A-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 226 Set plate Spring pin Tilt stopper Bushing Guide Friction spring Reverse lock lever spring Bushing Washer Shoulder screw – Reverse lock lever grip Stopper Reverse lock lever Washer Washer Copilot assembly 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-7...
  • Page 227 Clamp/Swivel Bracket and Driveshaft Housing Torque Ref. No. Qty. Description lb‑in. lb‑ft Transom screw (M8 x 85) Washer 13.5 – Page 5A-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 228 Clamp/Swivel Bracket and Driveshaft Housing Clamp Bracket Components (Manual Tilt) 48 49 47 48 27 28 63293 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-9...

  • Page 229: Steering Arm And Copilot Components

    Clamp/Swivel Bracket and Driveshaft Housing Steering Arm and Copilot Components 64416 Page 5A-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 230 Upper damper Washer Locknut 27.0 – 19.9 Copilot assembly Locknut 11.0 97.3 – Washer Washer Copilot handle Disc Screw (M6 x 16) 53.1 – Copilot plate Washer O‑ring Copilot threaded rod 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-11...

  • Page 231: Driveshaft Housing Components

    Clamp/Swivel Bracket and Driveshaft Housing Driveshaft Housing Components 64417 Page 5A-12 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 232 Screw 53.1 – Rubber seal Extension housing (driveshaft extension) Screws (driveshaft extension) 24.0 – 17.7 Driveshaft bushing (driveshaft extension) Stopper (driveshaft extension) Screw (M6 x 12) (driveshaft extension) 53.1 – 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-13...

  • Page 233: Driveshaft Housing Cover Components

    Clamp/Swivel Bracket and Driveshaft Housing Driveshaft Housing Cover Components 64676 Page 5A-14 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 234 Power tilt switch (power tilt models) Gasket (power tilt models) Switch box (power tilt models) Switch box grommet (power tilt models) Screw (power tilt models) 22.1 – Top cowl seal 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-15...

  • Page 235: Driveshaft Housing Covers

    To completely remove the port cover for models with power tilt: Disconnect the green and blue power tilt wires from the power tilt relays. Blue (up) tilt relay terminal and wire Green (down) tilt relay terminal and wire 63064 Page 5A-16 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 236: Installation

    The front cowl houses the fuel connection, the diagnostic light, and the optional start push‑button. It also has a catch for the top cowl. Removal Remove the driveshaft housing covers. Refer to Driveshaft Housing Covers. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-17...

  • Page 237: Installation

    Notch for upper shift shaft boot Tabs for midplate Bullet connectors for diagnostic light Fuel inlet fitting Screw securing fuel inlet fitting 63483 Install the driveshaft housing covers. Refer to Driveshaft Housing Covers. Page 5A-18 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 238: Idle Exhaust Port Cover

    4 (upper left corner), and that the hose is connected to the fitting. Follow the sequence marked on the cover, and tighten the screws to the specified torque. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-19...

  • Page 239: Powerhead/Midsection Assembly Separation

    Completely remove both driveshaft housing covers. Refer to Driveshaft Housing Covers. For electric start models, remove the starter motor. Refer to Section 2B ‑ Starter Motor Removal. Remove the upper shift shaft: Page 5A-20 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 240 Attach the engine lifting eye to an overhead hoist or other suitable lifting equipment. Remove the slack from the hoist. 62883 Remove the lower mount. Refer to Lower Mount. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-21...

  • Page 241: Installation

    For tiller handle models, install the tiller handle, shift cable, and throttle cables. Complete the throttle cable adjustments, as required. Refer to Section 7B ‑ Tiller Handle. Install the driveshaft housing covers. Refer to Driveshaft Housing Covers. Page 5A-22 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 242: Engine Mount Replacement

    Attach the engine and driveshaft housing to the steering arm/swivel bracket. Refer to Powerhead/Midsection Assembly Separation. Lower Mount Removal Remove the screw that secures the two continuity wires to the port side of the lower mount. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-23...
  • Page 243 Smaller rubber mount (one on each side) Lower continuity wire (from driveshaft housing to lower mount) Thrust plate Port half of the lower mount bracket Large rubber mount 62946 Page 5A-24 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 244: Clamp Brackets, Swivel Bracket - Power Tilt Models

    Cut the cable ties securing the power tilt pump wires to the inside of the clamp bracket. Remove the tilt tube cap and locknut. Remove the power tilt lower pivot screw and washer. Remove the screw securing the ground cable to the power tilt unit. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-25...
  • Page 245 Secure the power tilt pump wires to the inside of the port clamp bracket with two cable ties. Secure the power tilt pump wires to the outside of the port clamp bracket with a P‑clip. Page 5A-26 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 246 Tilt tube locknut 24.0 – 17.7 11. Route the power tilt pump wires through the grommet in the port driveshaft housing cover. Ensure that the grommet is properly seated in the cover. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-27...
  • Page 247 Remove the tilt tube cap and nut. Remove the starboard clamp bracket. Ground cable screw Lower pivot pin screw (M8 x 20) and washer Tilt lock pin, locknut, and washer 63485 Page 5A-28 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 248 Thread the nut onto the tilt tube to the end of the threads. 10. Push the tilt tube in until the nut is seated in the hex cavity. 11. Tighten the port tilt tube locknut to the specified torque. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-29...

  • Page 249: Steering Arm Removal

    Remove one locknut to remove the copilot handle. Remove two screws with washers to remove the remaining copilot components from the swivel bracket. Copilot handle Locknut Screw with washer 63341 Page 5A-30 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 250: Power Tilt Removal

    Remove the upper pivot pin. 10. Remove the lower pivot pin and remove the power tilt unit. Screw and washer Upper pivot pin Lower pivot pin screw and washer Power tilt unit 35122 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-31...

  • Page 251: Swivel Bracket Removal

    Remove the swivel bracket. 35129 Swivel Bracket Inspection Remove the bushings from the swivel bracket. Inspect for wear. Replace if necessary. Clean the swivel bracket. Apply 2‑4‑C with PTFE to the bushings. Page 5A-32 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 252: Swivel Bracket Installation

    Swivel Bracket Installation Clean the tilt tube and clamp brackets. Insert the tilt tube through the port clamp bracket. Install a washer onto the tilt tube. Install the carrying handle. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-33...

  • Page 253: Power Tilt Installation

    Install the lower pivot pin through the clamp brackets and the power tilt unit. Install the upper pivot pin through the swivel bracket and the power tilt rod eye. Install the lower pivot pin screw. Tighten the screw to the specified torque. Page 5A-34 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 254: Steering Arm Installation

    Install a washer onto the steering arm shaft. Insert the steering arm into the swivel bracket. Ensure that the lower bushing remains in the swivel bracket. For tiller handle models: 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-35...
  • Page 255 Attach the outboard to the swivel bracket. Refer to Powerhead/Midsection Assembly Separation. IMPORTANT: Ensure that the upper mount locknuts are tightened to the specified torque. Description lb‑in. lb‑ft Upper mount locknut 27.0 – 19.9 Page 5A-36 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 256: Clamp Brackets, Swivel Bracket - Manual Tilt Models

    Install the clamp bracket partially onto the tilt tube and clamp bracket spacer. Lubricate the plastic washer on the tilt tube with 2‑4‑C with PTFE. Tube Ref No. Description Where Used Part No. 2-4-C with PTFE Tilt tube washer 92-802859A 1 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-37...
  • Page 257 Push the tilt tube towards the starboard side to allow the starboard nut to be removed. 63339 Remove the nut. Remove the nut and washer from the clamp bracket spacer. Remove the tilt pin. Remove the starboard clamp bracket. Page 5A-38 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 258 Push the tilt tube in until the nut is seated in the hex cavity. Tighten the port tilt tube locknut to the specified torque. Install both caps onto the tilt tube. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-39...

  • Page 259: Steering Arm Removal

    Remove one locknut to remove the copilot handle. Remove two screws with washers to remove the remaining copilot components from the swivel bracket. Copilot handle Locknut Screw with washer 63341 Page 5A-40 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 260: Swivel Bracket Removal

    Remove the swivel bracket and bushings from the tilt tube. Bushing Swivel bracket 63344 Swivel Bracket Inspection Remove the bushings from the swivel bracket. Inspect for wear. Replace if necessary. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-41...
  • Page 261 Spring Bushing Washer Shoulder screw Spring Pivot guide Bushing Spring pin Plate Screw Tilt stopper 63345 Tube Ref No. Description Where Used Part No. Loctite® 222 Threadlocker Shoulder screw 92-809818 Page 5A-42 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 262: Swivel Bracket Installation

    Install the port clamp bracket onto the tilt tube and clamp bracket spacer. Ensure that the tilt lock guide bar is in the channels of the clamp brackets. Tilt lock guide bar Channel in the starboard clamp bracket (port similar) 63348 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-43...

  • Page 263: Steering Arm Installation

    Washer Copilot threaded rod 63349 Install one disc and washer (item c, shown following) onto the threaded rod. Attach the plate to the steering arm with two screws and washers. Page 5A-44 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 264 IMPORTANT: Ensure that the upper mount locknuts are tightened to the specified torque. Be certain to coat the threads of the tiller handle screws with Loctite® 271 Threadlocker, and ensure that the tiller handle screws are tightened to the specified torque. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-45...

  • Page 265: Driveshaft Housing Removal

    Nut (one each side) Steering arm 64100 Remove the powerhead gasket. Remove the driveshaft seal. 10. Remove the rubber seal from the driveshaft housing. Powerhead gasket Dowel pin Driveshaft seal Rubber seal 64101 Page 5A-46 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 266: Driveshaft Housing Installation

    Install the rubber seal onto the driveshaft housing. Install the driveshaft seal. Install the powerhead gasket. Powerhead gasket Dowel pin Driveshaft seal Rubber seal 64101 Install the driveshaft housing onto the steering arm. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-47...

  • Page 267: Shift Operation

    Avoid injury or death from loss of steering control. ProKicker centering straps prevent the outboard from turning when tilted up. If using a steering tie bar to a second outboard, disconnect the steering tie bar to allow steering of the second outboard before operating the boat. Page 5A-48 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 268: Removal

    53.1 – Upper engine mount screw – Repeat the steps to install the port kicker strap. Install the driveshaft housing cover onto the driveshaft housing. Refer to Driveshaft Housing Cover. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5A-49...
  • Page 269 Clamp/Swivel Bracket and Driveshaft Housing Notes: Page 5A-50 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 270 Cowl‑Mounted Tilt Switch..........5B-9 Power Tilt Pump...............5B-24 Removal..............5B-9 Power Tilt Pump Disassembly........5B-24 Installation..............5B-9 Power Tilt Pump Reassembly........5B-26 Troubleshooting the Power Tilt System......5B-10 Power Tilt Installation............5B-29 Preliminary Troubleshooting Steps......5B-10 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-1...

  • Page 271: Power Tilt Specifications

    The remote control (or tiller handle) has a switch that tilts the outboard up for trailering or down for operation. • At low idle speed, the outboard can also be tilted to permit shallow water operation. • The outboard cannot be trimmed at speeds above low idle. Page 5B-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 272 Power Tilt Notes: 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-3...

  • Page 273: Power Tilt Components

    Power Tilt Power Tilt Components 33822 Page 5B-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 274 – Bolt (M5 x 25) 46.0 – Filter Coupling O‑ring Motor bracket assembly Oil seal O‑ring Cable tie Screw – Armature assembly Housing Screw 46.0 – Screw (M5) 46.0 – 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-5...

  • Page 275: Theory Of Operation

    When the engine is not running, the outboard may be tilted to the full up position by opening the manual release valve. Page 5B-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 276: Power Tilt Features And Operation

    Turn out the manual tilt release valve three turns counterclockwise. This allows manual tilting of the outboard. Tilt the outboard to the desired position and tighten the manual tilt release valve. 31967 Tilt‑in Stop Adjustment NOTE: The outboard should be positioned against the tilt‑in stop pins during operation. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-7...

  • Page 277: Check Fluid And Purge The Power Tilt System

    Angle adjusted properly (bow slightly up) Check Fluid and Purge the Power Tilt System Check Fluid Tilt the outboard to the full up position and engage the tilt support lever. 4530 Page 5B-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 278: Purging The Power Tilt System

    Remove the fill plug and check the fluid level. The fluid level should be even with the bottom of the fill hole. Add Quicksilver or Mercury Precision Lubricants Power Trim and Steering Fluid. If not available, use automotive automatic transmission fluid (ATF).

  • Page 279: Troubleshooting The Power Tilt System

    Wait 24 hours and measure the distance again. Cylinder rod Rod eye Cylinder cap Measured distance 36840 Power Tilt System Leakage Specification Cylinder rod leak‑down in 24 hour period Less than 55 mm (2.2 in.) Page 5B-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 280: Hydraulic System Troubleshooting

    Tilt motor does not run when the tilt button is pressed 1, 3, 4, 5, 6, 7 Tilt system tilts opposite of buttons Tiller handle mounted tilt buttons do not activate the tilt system 3, 4, 5, 6 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-11...

  • Page 281: Power Tilt Relay Test

    DC voltage Battery voltage (~12 V) Replace the power tilt relay if it does not switch either lead to positive. Reconnect the heavy gauge pump wires to the tilt control relay. Page 5B-12 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 282: Wire Color Code Abbreviations

    Pink Purple White Yellow Light Dark Tilt System Wiring Diagrams NOTE: The numbered callouts in these wiring diagrams correspond to test points identified in the following Tilt System Troubleshooting Charts 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-13...
  • Page 283 M N P 63522 Starter solenoid Battery 15‑amp fuse Tilt up relay Tilt down relay Power tilt assembly Engine harness 14‑pin connector Tiller handle harness 14‑pin connector Tiller handle tilt switch Page 5B-14 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 284: Tilt System Troubleshooting Charts

    Tilt switch on side mount remote control Tilt System Troubleshooting Charts Troubleshooting the Down Circuit NOTE: Refer to the preceding wiring diagrams for test points when troubleshooting the electrical systems. Test points are specified by number. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-15...
  • Page 285 Wire is open between points 7 and 8. and black lead to ground. battery voltage at No battery voltage measured: point 7. Press the up tilt button. • Go to step 4. Page 5B-16 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 286 • Check • Tilt switch. • All tilt harness connections for loose or corroded connections. • Pinched or severed wires. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-17...

  • Page 287: Power Tilt Removal

    Tilt cylinder rod pin retaining screw and washer Tilt cylinder rod pin 63702 Retract the power tilt cylinder rod. Disconnect the battery cables from the battery. Disconnect the power tilt electrical wires. Remove the ground wire. Page 5B-18 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 288: Manual Release Valve Removal And Repair

    Extend the tilt cylinder rod to the full up position. Slowly remove the power tilt reservoir fill plug. Drain the power tilt fluid. Remove the snap ring. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-19...

  • Page 289: Power Tilt Motor

    Drain the power tilt fluid. Remove the wire harness retaining screw. Remove the two 4 mm internal hex screws securing the motor assembly to the power tilt pump and cylinder assembly. Page 5B-20 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 290: Power Tilt Motor Disassembly, Inspection, And Repair

    8438 Remove the armature from the motor housing. Test for Short Test armature on a growler. Follow the growler manufacturer's test instructions. Indication of a short requires replacement of armature. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-21...
  • Page 291 Brush replacement is required if brushes are pitted, chipped, or if the distance between the brush pigtail and end of brush holder slot is less than 1.6 mm (0.063 in.). Brush Replacement Remove the three screws securing the brush and breaker components to the motor bracket. Remove the breaker. Page 5B-22 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 292: Power Tilt Motor Reassembly

    Install the breaker and the brush into the slots. Blue wire Green wire Screw Brush holder Brush Spring Breaker Motor bracket O‑ring 8425 Hold the brushes in the slots while installing the armature into the motor bracket. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-23...

  • Page 293: Power Tilt Pump

    Slowly remove the power tilt reservoir fill plug. Drain the power tilt fluid. Remove the wire harness retaining screw. Remove the power tilt motor by removing the two 4 mm internal hex screws. Page 5B-24 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 294 10. Remove the three internal hex screws securing the power tilt pump to the power tilt assembly. Power tilt pump Internal hex screw (5 mm x 20) Internal hex screw (5 mm x 25) 8441 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-25...

  • Page 295: Power Tilt Pump Reassembly

    Down orifice screen 8452 Power Tilt Pump Reassembly Install two new lubricated O‑rings in the power tilt housing. Install a new lubricated O‑ring on orifice. Install the filter and orifice. Page 5B-26 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 296 Power tilt pump Internal hex screw (5 mm x 20) Internal hex screw (5 mm x 25) 8441 Description lb. in. lb. ft. Pump mounting screws Install a clean pump filter. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-27...
  • Page 297 4 mm internal hex screws Wire harness attaching screw Tube Ref No. Description Where Used Part No. Power Trim and Steering Power tilt system 92-858074K01 Fluid Page 5B-28 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 298: Power Tilt Installation

    Install the washer and retaining screw into the pivot pin. Tighten the screws to the specified torque. Clamp bracket Pivot pin Washer (2) Retaining screw (2) Pivot pin bushing (2) Power tilt assembly 8736 Description lb‑in. lb‑ft Pivot pin retaining screw – 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-29...
  • Page 299 63064 Connect the battery cables to the battery. 10. Install the bushings into the swivel bracket. Bushing (2) Swivel bracket Clamp bracket 8730 11. Extend the power tilt cylinder rod. Page 5B-30 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 300 16. Cycle the outboard up and down several times to purge air from the system. 17. Check the power tilt fluid level. Refer to Check Fluid and Purge the Power Tilt System, preceding. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-31...
  • Page 301 Power Tilt Notes: Page 5B-32 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 302 Water Pump, Driveshaft, and Shift Shaft Disassembly Water Pump Cover Assembly........6A-37 ................6A-18 Propeller Shaft and Bearing Carrier Installation..6A-38 Driveshaft Removal..........6A-21 Gear Housing Installation......... 6A-39 Forward Gear and Reverse Gear Inspection....6A-22 Propeller Installation..........6A-41 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-1...
  • Page 303 Spring Pin Removal Tool 91‑853996‑6 Aids in the removal of the spring pins 3423 Driveshaft Holding Tool 91‑804762 Holds the driveshaft while removing or installing the pinion gear nut 12519 Page 6A-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 304 Used as part of an assembly to provide upward force on the driveshaft to check forward gear backlash. Part of Pinion Bearing Installation Tool Assembly 91‑899015A02 37831 Backlash Preload Tool 91‑895195T04 Prevents forward gear movement when checking the forward gear backlash. 12520 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-3...

  • Page 305: Gearcase Specifications

    460 ml (15.6 fl oz) Gear lubricant type Premium Gear Lubricant or GL5 SAE 80W‑90 Pinion teeth Pinion height Floating Clutch Dog type (forward–neutral–reverse) Forward, reverse teeth Forward gear backlash 0.8–1.5 mm (0.030–0.059 in.) Page 6A-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 306 Gear Housing (2.15:1) Notes: 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-5...

  • Page 307: Gear Housing And Driveshaft

    Gear Housing (2.15:1) Gear Housing and Driveshaft 64672 Page 6A-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 308 Guide plate gasket Water pump guide plate Impeller Pump case liner Dowel pin Upper pump case Lower water pipe seal Screw 53.1 – Shim Ball bearing Driveshaft Pinion gear 35.0 – 25.8 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-7...

  • Page 309: Propeller Shaft

    Gear Housing (2.15:1) Propeller Shaft 64673 Page 6A-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 310 Thrust washer Reverse gear O‑ring Ball bearing Bearing carrier Needle bearing Oil seal Screw 79.6 – Propeller Propeller hardware kit Front thrust hub Washer Propeller nut 12.0 106.2 – Cotter pin 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-9...

  • Page 311: General Service Recommendations

    Before installing or removing a propeller, place the drive unit in neutral and engage the lanyard stop switch to prevent the engine from starting. Place a block of wood between the propeller blade and the anti‑ventilation plate. Page 6A-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 312: Gear Housing Removal

    Cotter pin Propeller nut 6523 Remove the propeller nut, flat washer, propeller, and front thrust washer from the propeller shaft. Turn the coupler to separate the upper and lower shift shafts. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-11...

  • Page 313: Gear Housing Disassembly

    IMPORTANT: It is recommended that during complete disassembly of the gear housing, all O‑rings and oil seals be replaced regardless of their appearance. Bearing Carrier Disassembly Remove the two screws securing the bearing carrier. Screws (2) 6532 Page 6A-12 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 314 Remove the bearing carrier and propeller shaft assembly from the gearcase. Propeller shaft Bearing carrier assembly 6545 NOTE: The cam follower is free to slide out of the propeller shaft. 62931 Propeller shaft Bearing carrier assembly Cam follower 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-13...
  • Page 315 If the reverse gear must be replaced, use a bearing puller assembly to remove the reverse gear from the reverse gear bearing. Bearing carrier assembly Reverse gear Bearing puller assembly 34379 Bearing Puller Assembly 91‑ 83165T Page 6A-14 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 316 NOTE: When removing the carrier seal, do not scar the carrier seal surface. If the carrier seal surface is damaged, replace the carrier. Torch lamp Bearing puller assembly Oil seal 34381 Bearing Puller Assembly 91‑ 83165T Torch Lamp 91‑ 63209 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-15...

  • Page 317: Propeller Shaft Disassembly

    Inspect the cam follower for wear. Replace the follower if it is worn. 62931 Propeller shaft Bearing carrier assembly Cam follower Remove the clutch pin retainer spring from the clutch. Page 6A-16 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 318 Inspect the needle bearing surface of the propeller shaft for pitting and wear. Replace the propeller shaft and needle bearing (in the bearing carrier) if wear or pitting is present. Replace the propeller shaft if any of the following exist: • Splines are twisted or worn 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-17...

  • Page 319: Water Pump, Driveshaft, And Shift Shaft Disassembly

    Installing the impeller with the vanes reversed from their original direction will result in vane breakage. Page 6A-18 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 320 Remove the screw and clamp securing the water pump base. 10. Use the pry points to remove the water pump base from the gear housing. The shift shaft will lift out with the base. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-19...
  • Page 321 14. Remove and replace the shift shaft O‑ring from the top of the water pump base. Apply 2‑4‑C with PTFE to the O‑ring before installation. Tube Ref No. Description Where Used Part No. 2-4-C with PTFE Shift shaft O-ring 92-802859A 1 Page 6A-20 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 322: Driveshaft Removal

    Spring pin removal tool Retainer pin Shift cam 62860 Spring Pin Removal Tool 91‑853996‑6 Driveshaft Removal Use the driveshaft holding tool to hold the driveshaft while removing the pinion nut. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-21...

  • Page 323: Forward Gear And Reverse Gear Inspection

    Inspect the forward gear ball bearing for roughness or excessive wear. If the bearing is in serviceable condition, do not remove the bearing from the gearcase. The removal process may damage the bearing and forward gear bushing. Page 6A-22 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 324 Inspect the forward and reverse gear clutch jaws for wear. Rounded jaws indicate the following: Improper shift cable or linkage adjustment Engine idle speed too high Shifting too slowly Forward gear teeth Propeller shaft bushing Clutch jaws 6699 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-23...

  • Page 325: Driveshaft Pinion Bearing Removal

    Inspect the pinion bearing for signs of damage. Page 6A-24 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 326: Driveshaft Inspection

    Driveshaft Inspection Inspect the splines at both ends of the driveshaft for a worn or twisted condition. Replace the driveshaft if either condition exists. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-25...

  • Page 327: Upper Driveshaft Bearing Inspection

    Tube Ref No. Description Where Used Part No. Premium Gear Lubricant Inside diameter and outside diameter of pinion bearing 92-858058K01 Page 6A-26 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 328: Forward Gear Bearing Installation

    Using a mandrel that contacts only the inner diameter of the bearing race, press the bearing onto the forward gear. Mandrel Forward gear bearing Forward gear 6716 Use a torch lamp to warm the gearcase in the forward gear bearing area. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-27...

  • Page 329: Bearing Carrier Assembly

    Install the seal with the seal face up. Using a suitable mandrel from the bearing mandrel kit, press the seal into the bearing carrier until seated. Mandrel Seal (install face up) 6763 Bearing Mandrel Kit 91‑ 83166M Page 6A-28 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 330 Use a torch lamp to warm the bearing carrier. Use a suitable mandrel to press the reverse gear assembly into the bearing carrier until the bearing is seated. Reverse gear assembly Bearing carrier Mandrel Torch lamp 6772 Bearing Mandrel Kit 91‑ 83166M Torch Lamp 91‑ 63209 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-29...

  • Page 331: Water Pump Base Assembly

    Apply 2‑4‑C with PTFE onto a new O‑ring and install the O‑ring onto the water pump base. Mandrel Seal O‑ring Water pump base 6831 Tube Ref No. Description Where Used Part No. 2-4-C with PTFE Apply to seal lips and O-rings 92-802859A 1 Page 6A-30 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 332: Propeller Shaft Assembly

    Insert the clutch cross pin through the clutch and propeller shaft until the clutch pin is flush with the clutch surface. Clutch pin Propeller shaft 6846 Install the thrust washer into the propeller shaft. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-31...

  • Page 333: Pinion Gear And Driveshaft Installation

    Lift the driveshaft slightly and install the pinion gear. It may be necessary to rotate the driveshaft slightly to engage the pinion gear with the splines of the driveshaft and forward gear teeth. Apply Loctite® 271 Threadlocker to the pinion nut threads. Page 6A-32 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 334: Forward Gear Backlash

    Secure the water pump base assembly to the gearcase with four M6 x 1 screws (obtain locally). Tighten the screws to the specified torque. Description lb‑in. lb‑ft Screw (M6 x 1) 53.1 – 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-33...
  • Page 335 Backlash Indicator Arm 91‑803133 12 Attach a dial indicator and dial indicator adapter to the gearcase, using a piece of threaded rod and two nuts (obtain locally). Page 6A-34 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 336: Shift Shaft And Water Pump Base Installation

    Inspect the shift shaft bracket, located on the underside of the water pump base. Replace it, if it is damaged. Description lb‑in. lb‑ft Shift shaft bracket screw 44.3 – Insert the shift shaft into the water pump base. Ensure that the new shift shaft O‑ring remains properly seated. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-35...
  • Page 337 Ensure that the sealing surfaces of the water pump base and the faceplate are clean. Using a new gasket, install the faceplate. Dowel pin (2) Faceplate (with new gasket beneath) Water pump base (gasket beneath) Shift shaft Clamp Screw and washer 62861 Page 6A-36 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 338: Water Pump Cover Assembly

    Lubricate the inside diameter of the water pump liner with 2‑4‑C with PTFE. Tube Ref No. Description Where Used Part No. 2-4-C with PTFE Inside diameter of the water pump liner 92-802859A 1 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-37...

  • Page 339: Propeller Shaft And Bearing Carrier Installation

    Screws (4) Water pump cover 62846 Description lb‑in. lb‑ft Water pump cover screws 53.1 – Propeller Shaft and Bearing Carrier Installation Apply 2‑4‑C with PTFE to the bearing carrier O‑ring. Page 6A-38 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 340: Gear Housing Installation

    Place the gear housing into reverse by pushing down on the lower shift shaft until it stops. A hard stop should be felt as the shift shaft spring pin comes to rest on the tabs at the bottom of the shift shaft bracket. Apply 2‑4‑C with PTFE to the driveshaft splines. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 6A-39...
  • Page 341 If the shift operation is not as described, check the coupler installation procedure. If the coupler installation procedure is correct, the gearcase is not properly assembled or internal parts are excessively worn and must be replaced. Page 6A-40 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 342: Propeller Installation

    Before installing or removing a propeller, place the drive unit in neutral and engage the lanyard stop switch to prevent the engine from starting. Place a block of wood between the propeller blade and the anti‑ventilation plate. Coat the propeller shaft splines with one of the following Mercury products: Tube Ref No.
  • Page 343 Gear Housing (2.15:1) Notes: Page 6A-42 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 344 Remote Control Components..........7A-6 Remote Models..............7A-10 Tiller Handle Models............7A-8 Throttle and Shift Linkage Removal......7A-10 Throttle and Shift Linkage Removal......7A-8 Shift Detent............... 7A-12 Shift Detent..............7A-9 Throttle and Shift Linkage Installation.......7A-12 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7A-1...
  • Page 345 Throttle and Shift Linkage Lubricants, Sealants, Adhesives Tube Ref No. Description Where Used Part No. 2-4-C with PTFE Shift shaft assembly detents and contact surfaces 92-802859A 1 Page 7A-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 346 Throttle and Shift Linkage Notes: 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7A-3...

  • Page 347: Throttle And Shift Components (Tiller Models)

    Throttle and Shift Linkage Throttle and Shift Components (Tiller Models) 29 30 64682 Page 7A-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 348 Ball joint connector Jam nut 26.6 – Throttle rod Screw 53.1 – Washer Bushing Throttle drum assembly Ball joint Throttle and shift cable bracket Screw 53.1 – Screw Cable latch 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7A-5...

  • Page 349: Remote Control Components

    Throttle and Shift Linkage Remote Control Components 64681 Page 7A-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 350 Detent spring Screw 53.1 – Starboard horizontal shift shaft bracket Port horizontal shift shaft bracket Horizontal shift shaft Vertical shift shaft Shift shaft coupler 35.4 – Jam nut 35.4 – Grommet 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7A-7...

  • Page 351: Tiller Handle Models

    Remove the four screws securing the two shift lever shaft brackets. The front cowl will come loose with the brackets. 10. Disconnect the vertical shift shaft from the shift lever, and remove the shift lever. Shift lever shaft bracket screws (4) Front cowl Vertical shift shaft 63462 Page 7A-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 352: Shift Detent

    10. Install the shift link, using one screw, two washers (one each side), and one bushing. Tighten the screw to the specified torque. Description lb‑in. lb‑ft Shift link screw 53.1 – 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7A-9...

  • Page 353: Remote Models

    Remove the air box and recoil starter. • It is easiest to remove and install these two items together. • Refer to Section 3C ‑ Air Box Removal and Section 8A ‑ Recoil Starter. Page 7A-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 354 Remove the throttle link. Remove three screws to remove the throttle and shift bracket. Remove the retaining clip and washer and remove the shift lever rod from the shift arm. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7A-11...

  • Page 355: Shift Detent

    Apply 2‑4‑C with PTFE to the shift shaft assembly detents and contact surfaces. Tube Ref No. Description Where Used Part No. 2-4-C with PTFE Shift shaft assembly detents and contact surfaces 92-802859A 1 Page 7A-12 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 356 Throttle and shift bracket screws Retaining clip and washer Screw, two washers, and bushing Shift link 63465 Description lb‑in. lb‑ft Throttle and shift bracket screws (3) 53.1 – Shift link screw 53.1 – 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7A-13...
  • Page 357 Refer to Section 8A ‑ Recoil Starter Installation and Section 3C ‑ Air Box Installation. 15. Adjust the interlock cable jam nuts to remove any slack in the cable. 16. Install the starboard driveshaft housing cover. Refer to Section 5A ‑ Driveshaft Housing Covers. Page 7A-14 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 358 Tiller Handle Yaw...............7B-8 Tiller Handle Installation...........7B-17 Tiller Handle Removal............7B-9 Shift Cable Installation............. 7B-18 Tiller Handle Disassembly..........7B-9 Throttle Cable Installation..........7B-21 Throttle Cable Case............7B-11 Throttle Cable Adjustments..........7B-22 Disassembly/Inspection..........7B-11 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7B-1...

  • Page 359: Tiller Handle Features

    Push the lock release lever down to allow the tiller handle to be lowered. • Turn the adjustment knob to raise or lower the tiller handle in its operating position. Tiller lock release lever Tiller handle adjustment knob 63082 Page 7B-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 360 The tiller handle can be configured for right‑hand or left‑hand throttle operation; refer to Throttle Cable Installation. 63086 • Models with power tilt have a tilt switch located on the underside of the tiller handle. 63906 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7B-3...

  • Page 361: Tiller Handle Components

    Tiller Handle Tiller Handle Components 35 36 64701 Page 7B-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 362 Spare clip decal Lanyard cord assembly Spare lanyard clip Pan head screw 20.3 – Flat spring shift detent 2‑pin male connector (for stop switch assembly) Stop switch assembly (without connector) 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7B-5...
  • Page 363 – Self‑tapping hex head screw 17.7 – Pulley cover Throttle cable pulley Throttle cable case Tiller handle with tilt harness assembly Tiller handle harness assembly Grommet Plastic nut 17.7 – Page 7B-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 364 Tiller Handle Tiller Handle Components 35 36 64701 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7B-7...

  • Page 365: Tiller Handle Yaw

    Lift the clamp with your fingers and rotate the tiller handle to the desired angle. Clamp Locknut Center demarcation 63260 Install the locknut, tighten it to the specified torque, and install the rubber boot. Page 7B-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 366: Tiller Handle Removal

    Tiller handle mounting screws (2) Tiller handle 63079 Tiller Handle Disassembly Remove the lanyard cord and the hex nut securing the lanyard stop switch to the underside of the tiller handle. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7B-9...
  • Page 367 Friction knob Large washer Cotter pin Small washer Spring Throttle shaft clamp 63431 Remove the screw that secures the throttle shaft bracket. Lift up to remove the bracket. Page 7B-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 368: Throttle Cable Case

    Power tilt model shown, manual tilt model similar Screws (2) Shift detent spring Tiller handle harness Shift handle screw 63432 Throttle Cable Case Disassembly/Inspection Remove the screw and remove the cover from the cable holder. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7B-11...

  • Page 369: Assembly

    Tube Ref No. Description Where Used Part No. 2-4-C with PTFE Throttle cable end barrels, pulley face, and pulley O.D. 92-802859A 1 Install the pulley with the cables into the case. Page 7B-12 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 370: Tiller Handle Assembly

    Install the detent spring and secure it with two screws. Power tilt model shown, manual tilt model similar Screws (2) Shift detent spring Tiller handle harness Shift handle screw 63432 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7B-13...
  • Page 371 Install the throttle handle: Position the throttle cable pulley housing. Install the friction clamp on the throttle handle shaft. Slide the throttle handle partially over the end of the tiller handle chassis. Page 7B-14 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 372 10. Route the wires through the notches in the tiller handle housing. Secure the wires with the cable ties, ensuring that they will not interfere with the throttle shaft or the cover fit. Throttle shaft bracket Screw Cable ties (2) 63443 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7B-15...
  • Page 373 The specified torque is a baseline value that may be varied according to operator preference. 14. Insert one large and one small grommet. Small grommet Large grommet Screw head Belleville washer Flat washer Flange spacer Locknut 63428 Page 7B-16 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 374: Tiller Handle Installation

    29.5 Route the tiller handle harness through the grommet. Connect the 14‑pin connector to the engine harness. Connect the throttle and shift cables. Refer to Throttle and Shift Cable Installation. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7B-17...

  • Page 375: Shift Cable Installation

    Couple the upper and lower vertical shift shafts: Ensure that the upper and lower shift shafts are separated. Turn the jam nut on the lower vertical shift shaft until it is all of the way down. Page 7B-18 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 376 Use a flat‑blade screwdriver or other suitable tool to ensure that the detent springs are fully seated in the reverse detent. Tighten the shift detent screw to the specified torque. Description lb‑in. lb‑ft Shift detent screw 53.1 – 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7B-19...
  • Page 377 Verify the detent spring is fully seated in the horizontal shift shaft cam notch. Shift the tiller into neutral. • Verify no engagement or clutch drag in neutral. • Verify the detent is fully seated in the horizontal shift shaft cam notch. Page 7B-20 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 378: Throttle Cable Installation

    NOTE: The standard installation is with counterclockwise rotation of the throttle grip from idle to WOT. To change throttle grip rotation to clockwise, swap the cable positions on the throttle drum and bracket. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7B-21...

  • Page 379: Throttle Cable Adjustments

    Adjust the cable lengths by using the jam nuts to bring the idle stop on the throttle drum against the throttle stop. Make adjustments to the lower cable first. Remove slack in the upper cable by adjusting the upper jam nuts. Do not overtighten. Page 7B-22 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 380 Rotate the tiller twist grip to the wide‑open throttle (WOT) position. Ensure that the wide‑open throttle stop on the throttle drum rests against the throttle stop. 63261 Throttle drum idle stop Throttle stop Throttle cable jam nut (one of four) Throttle drum WOT stop 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 7B-23...
  • Page 381 Tiller Handle Notes: Page 7B-24 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 382 Section 8A - Recoil Starter Table of Contents Recoil Starter Components..........8A-4 Recoil Starter Assembly.............8A-7 Recoil Starter Removal............8A-6 Recoil Starter Installation..........8A-11 Recoil Starter Disassembly..........8A-6 Neutral Interlock Cable Adjustment......... 8A-12 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 8A-1...
  • Page 383 Threads of the friction plate retaining screw Loctite® 271 Threadlocker 92-809819 Threads of the recoil starter assembly screws Recoil housing 2-4-C with PTFE Starter pawl bore on the sheave 92-802859A 1 Friction plate Page 8A-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 384 Recoil Starter Notes: 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 8A-3...

  • Page 385: Recoil Starter Components

    Recoil Starter Recoil Starter Components 64650 Page 8A-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 386 Cam gear cover Vent tank Screw Grommet Starter rope Spring Tapping screw Bushing Sheave Starter pawl Starter pawl guide Return spring Starter shaft screw 53.1 – Friction plate Friction plate spring 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 8A-5...

  • Page 387: Recoil Starter Removal

    Remove the handle cap from the recoil handle. Cut or untie the recoil rope from the recoil handle. Slowly allow the sheave to unwind completely. Rotate the sheave clockwise to disengage the recoil spring from the sheave. Page 8A-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 388: Recoil Starter Assembly

    12. Inspect the starter rope for damage. Replace as required. Recoil Starter Assembly WARNING Uncontrolled release of the rewind spring can cause serious injury. Wear eye protection when servicing the rewind starter in case the spring uncoils. 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 8A-7...
  • Page 389 Assemble and install the starter pawl: Assemble the starter pawl as shown. 9728 Lubricate the starter pawl bore on the sheave with 2‑4‑C with PTFE. Install the starter pawl return spring onto the sheave. Page 8A-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 390 Assemble and install the friction plate: Install the friction plate spring onto the friction plate. Lubricate the friction plate with 2‑4‑C with PTFE. Friction plate spring Friction plate Lubricate with 2‑4‑C with PTFE 9740 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 8A-9...
  • Page 391 Wind the sheave three turns counterclockwise to preload the recoil spring. Recoil rope Sheave notch Recoil rope guide Recoil housing opening 63304 Allow the recoil rope to retract into the sheave. Ensure the recoil rope retracts and extends fully. Page 8A-10 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...

  • Page 392: Recoil Starter Installation

    Apply Loctite® 271 Threadlocker to the threads of the three recoil starter assembly screws. Tube Ref No. Description Where Used Part No. Loctite 271 Threadlocker Threads of the recoil starter assembly screws 92-809819 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 8A-11...

  • Page 393: Neutral Interlock Cable Adjustment

    Neutral interlock cable ball Centering mark 63087 Tighten the lower jam nut. Verify that the ball centers when shifting from forward and when shifting from reverse. Adjust the jam nuts as necessary. Page 8A-12 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 394 15/20 EFI FourStroke with Electric Start, Tiller Handle, 15/20 EFI FourStroke, Electric Start, Remote Control..9A-5 and Power Tilt..............9A-7 15/20 EFI FourStroke with Electric Start, Tiller Handle, and Manual Tilt...............9A-6 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 9A-1...
  • Page 395 Color Diagrams Notes: Page 9A-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 396 Color Diagrams Notes: 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 9A-3...

  • Page 397: 15/20 Efi Fourstroke, Manual Start, Manual Tilt

    14 - Cowl‑mounted start switch (not used) 30 - Warning light (signal) 15 - Not used 31 - Engine control module (ECM) 16 - Tiller models: Tiller handle stop push button Page 9A-4 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 398 15/20 EFI FourStroke Manual Start, Manual Tilt 1 2 3 4 1 2 3 1 2 3 1 2 3 1 2 3 4 1 2 3 BLK/RED GRN/ORN RED/WHT RED/WHT RED/WHT BLK/GRN BLK/YEL BLK/WHT LT GRN/RED LT GRN/BLK GRN/RED BLU/WHT GRN/YEL GRN/WHT...
  • Page 399 15/20 EFI FourStroke Electric Start, Remote Control 1 2 3 4 1 2 3 1 2 3 1 2 3 1 2 3 4 1 2 3 BLK/RED GRN/ORN RED/WHT RED/WHT RED/WHT BLK/GRN BLK/YEL BLK/WHT LT GRN/RED LT GRN/BLK GRN/RED BLU/WHT GRN/YEL GRN/WHT...

  • Page 400: 15/20 Efi Fourstroke, Electric Start, Remote Control

    34 - Tach signal 17 - Cowl‑mounted start switch (not used) 35 - Warning light (signal) 18 - Starter solenoid power (start signal) 36 - Engine control module (ECM) 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 9A-5...

  • Page 401: 15/20 Efi Fourstroke With Electric Start, Tiller Handle, And Manual Tilt

    Battery positive (+) 33 - Tach signal 16 - 15‑amp fuse (starting control circuit) 34 - Warning light (signal) 17 - Neutral start switch 35 - Engine control module (ECM) Page 9A-6 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 402 15/20 EFI FourStroke with Electric Start, Tiller Handle, and Manual Tilt 1 2 3 4 1 2 3 1 2 3 1 2 3 1 2 3 4 1 2 3 BLK/RED GRN/ORN RED/WHT RED/WHT RED/WHT BLK/GRN BLK/YEL BLK/WHT LT GRN/RED LT GRN/BLK GRN/RED BLU/WHT...
  • Page 403 15/20 EFI FourStroke with Electric Start, Tiller Handle, and Power Tilt 1 2 3 4 1 2 3 1 2 3 1 2 3 1 2 3 4 1 2 3 BLK/RED GRN/ORN RED/WHT RED/WHT RED/WHT BLK/GRN BLK/YEL BLK/WHT LT GRN/RED LT GRN/BLK GRN/RED BLU/WHT...

  • Page 404: 15/20 Efi Fourstroke With Electric Start, Tiller Handle, And Power Tilt

    39 - Tach signal 18 - Cowl‑mounted start switch 40 - Warning light (signal) 19 - Not used 41 - Engine control module (ECM) 20 - Tiller handle stop push button 90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 9A-7...
  • Page 405 Color Diagrams Notes: Page 9A-8 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017...
  • Page 406 Parc Industriel de Petit-Rechain 41-71 Bessemer Drive P.O. Box 1939 B-4800 Verviers, Belgium Dandenong South, Victoria 3175 Australia Fond du Lac, WI 54936-1939 USA © Mercury Marine. All rights reserved. 90-8M0125265 NOVEMBER 2017 Printed in U.S.A.

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