Compression Testing
Start and run outboard until it achieves operating temperature, then shut OFF.
Disconnect crankshaft position sensor (CPS) connector. Remove all spark plugs.
Advance throttle linkage to WOT.
Install compression tester’s hose attachment into spark plug hole (14 mm threads).
While cranking outboard with starter, note maximum pressure reading on gauge. Repeat procedure for each cylinder.
If engine shows a variation greater than 15 psi (100 kPa) between cylinders, check for:
• damaged cylinder head
• damaged pistons
• broken or stuck piston rings
• scored cylinder walls
Return throttle to idle position and reconnect CPS connector. Replace spark plugs. Refer to Spark Plug Indexing on p. 94.
Powerhead Removal
Protect against hazardous fuel spray. Before starting any fuel system service, carefully relieve fuel system pressure. Refer to Relieving Fuel System Pressure on p. 195.
To prevent accidental starting while servicing, twist and remove spark plug leads.
Remove lower motor covers. Lower Cover Removal on p. 103.
Remove flywheel cover and rear shroud.
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Remove air temperature sensor from air silencer. Remove the air silencer.
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Disconnect power trim connectors.
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- Tilt limit switch connector
- Sending unit connector
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- Tilt relay connector
Remove pin and washer from shift rod lever to release the lower shift rod.
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- Shift rod pin
Disconnect electrical harness from exhaust valve actuator (V4 models). It is not necessary to remove actuator from exhaust housing.
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- Actuator connector
Disconnect water overflow hose from vapor separator. Remove clamps and muffler assembly from rear of powerhead.
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- Overflow indicator hose
- Muffler clamps
Install Lifting Fixture, P/N 342672, on crankshaft. Tighten mounting screw securely using an Allen 1/4 in. hexagonal
wrench.
005260
Fasten appropriate chain hook to eye of tool an support weight of powerhead with hoist.
Remove the four small powerhead screws, seven large powerhead screws, and the upper mount screws.
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- Large powerhead screws
- Small powerhead screws
- Upper mount screws
Use a suitable tool to carefully separate the powerhead from exhaust housing.
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IMPORTANT: Do not damage the powerhead adapter mating surfaces when separating.
Powerhead Disassembly
Systems Removal
To simplify reassembly and wiring installation, lay out the various screws and clamps in the order of their proper location.
Remove the electric starter. Refer to Starter Removal on p. 168.
Remove fuel pump assemblies, fuel manifolds, and filter. Refer to FUEL COMPONENT SERVICING on p. 195.
Remove EMM and electrical harness with flywheel cover base, starter solenoid, and trim relay module. Refer to EMM SERVICING on p. 122.
Remove flywheel and stator. Refer to FLYWHEEL AND STATOR SERVICING on p. 162.
Remove oil pump, rear oil manifold, and oil circulation hoses. Refer to OIL COMPONENT SERVICING on p. 223.
Remove ignition coils and fuel injectors. Refer to Fuel Injector Service on p. 199.
IMPORTANT: Mark injectors for cylinder location before removal. All injectors must be installed in their original location. Improper injector installation can result in powerhead failure.
Remove throttle linkage. Refer to Throttle Linkage Removal on p. 243.
Remove shift linkage. Refer to Shift Linkage Removal on p. 243.
Remove the throttle body and reed plate assemblies. Refer to Intake Manifold Service on p. 201.
Remove pressure valve assembly. Refer to PRESSURE RELIEF VALVE SERVICING on p. 236.
