POWERHEAD
COMPRESSION TESTING
COMPRESSION TESTING
Start and run outboard until it achieves operating
temperature, then shut OFF.
Disconnect crankshaft position sensor (CPS) con-
nector. 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 maxi-
mum pressure reading on gauge. Repeat proce-
dure 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. 36.
170
POWERHEAD REMOVAL
WARNING
Protect against hazardous fuel spray.
Before starting any fuel system service,
carefully relieve fuel system pressure.
Refer to Relieving Fuel System Pressure
on p. 130.
To prevent accidental starting while ser-
vicing, twist and remove spark plug leads.
Remove lower motor covers. Lower Cover
Removal on p. 45.
Remove the recoil starter housing. Refer to
RECOIL STARTER REMOVAL on p. 281.
Remove exhaust relief muffler. Refer to Exhaust
Relief Muffler on p. 206.
Disconnect power trim connectors.
1
1. Connectors
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007784