TROUBLESHOOTING
SERVICE MANUAL NUMBER 24
Water on Top of Pistons
Cause
Special Information
Operator shut engine off at high rpm
Engine out of tune, poor fuel, high idle
rpm, timing set too high
Engine “diesels” or tries to run backwards
NOTE: The term “diesel” refers to an engine’s tendency to run on after the key has been
turned to the OFF position.
Rain water running into flame arrestor
Spark plug misfiring
Hatch cover
Improper combustion causes moisture in
the air to accumulate in the cylinder
Backwash through the exhaust system
Improper engine or exhaust hose installa-
tion
Cracked exhaust manifold
Improper manifold to elbow gasket instal-
lation
Loose cylinder head bolts
Blown cylinder head gasket
Cracked valve seat
Check for warped cylinder head or cylin-
der block
Check cylinder heads, cylinder block, and
intake manifold
Porous or cracked casting
Water in Crankcase Oil
Cause
Special Information
Boat has been submerged or bilge water
was high enough to run in through dipstick
tube
Water in boat bilge
Water seeping past piston rings or valves Refer to “Water on Top of Pistons”
Defective thermostat, missing thermostat;
Engine running cold
prolonged idling in cold water
Intake manifold leaking near a water pas-
sage
Check cylinder head, cylinder block and
Cracked or porous casting
intake manifold
Index
Page 1C-26
90-861327--1 OCTOBER 1999
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 305 CID, Mercury MerCruiser 350 CID |
| Model Year | 1998, 1999, 2000, 2001 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(1 votes, average: 4 out of 4)
Marine readers have rated Mercury MerCruiser Engines Service Manual Number 24 GM V-8 305 CID 350 CID 4.0 out of 4.0 based on 1 product reviews. Great performance engine.
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