3A - 8 - ENGINES
90-816462 2-695
Bearing Failures
Overlay Gone from
Entire Surface
70436
Scratched
by Dirt
Lack of Oil
Improper Seating
Tapered Journal
Radius Ride
Fatigue Failure
Scratches
Overlay Wiped
Out
Dirt Imbedded
into Bearing
Material
Bright (Polished)
Sections
Radius Ride
Craters or Pockets
Piston Failures
Pre-Ignition
Pre-ignition is abnormal fuel ignition, caused by com-
bustion chamber hot spots. Control of the start of igni-
tion is lost, as combustion pressure rises too early,
causing power loss and rough running. The upward
motion on the piston is opposed by the pressure rise.
This can result in extensive damage to the internal
parts from the high increase in combustion chamber
temperature.
72424
Pre-Ignition Damage
PRE-IGNITION CAUSES
1. Hot spots in the combustion chamber from glow-
ing deposits (due in turn to the use of improper oils
and/or fuels).
2. Overheated spark plug electrodes (improper heat
range or defective plug).
3. Any other protuberance in the combustion cham-
ber, such as an overhanging piece of gasket, an
improperly seated valve or any other inadequate-
ly cooled section of material which can serve as
a source.
Engine failures, which result from the foregoing con-
ditions, are beyond the control of Mercury Marine;
therefore, no warranty will apply to failures which oc-
cur under these conditions.
Summary of Contents for 13
Page 1: ...13 Printed in U S A 90 816462 2 695 1995 Brunswick Corporation GM 4 Cylinder MARINE ENGINES ...
Page 2: ...90 816462 2 695 0 ...
Page 7: ...1 A IMPORTANT INFORMATION GENERAL INFORMATION 72000 ...
Page 15: ...1 B 50617 IMPORTANT INFORMATION MAINTENANCE ...
Page 36: ...1 C IMPORTANT INFORMATION TROUBLESHOOTING ...
Page 74: ...2 A 50633 REMOVAL AND INSTALLATION 4 CYL ALPHA ONE DRIVE ...
Page 88: ...3 A 26790 ENGINE 181 CID 3 0L 4 CYLINDER GM ENGINE ...
Page 137: ...4 A 72079 ELECTRICAL SYSTEMS STARTING SYSTEM ...
Page 170: ...4 B 71855 ELECTRICAL SYSTEMS IGNITION SYSTEM ...
Page 197: ...ELECTRICAL SYSTEMS CHARGING SYSTEM 4 C 72078 ...
Page 237: ...4 D 72747 ELECTRICAL SYSTEMS INSTRUMENTATION ...
Page 250: ...4 E 72938 ELECTRICAL SYSTEMS WIRING DIAGRAMS ...
Page 264: ...5 A FUEL SYSTEM FUEL PUMP ...
Page 271: ...5 B 72681 FUEL SYSTEM MERCARB 2 BARREL CARBURETOR ...
Page 300: ...6 A 50628 COOLING SYSTEM SEAWATER COOLED MODELS ...
Page 309: ...6 B 73665 COOLING SYSTEM CLOSED COOLING MODELS ...
Page 325: ...C 6 EXHAUST SYSTEM MANIFOLD ...
Page 331: ...7 A 71317 POWER STEERING PUMP ...