ENGINES - 3A - 9
90-816462 2-695
Detonation
Detonation, commonly called “fuel knock,” “spark
knock” or “carbon knock,” is abnormal combustion of
the fuel which causes the fuel to explode violently.
The explosion, in turn, causes overheating or dam-
age to the spark plugs, pistons, valves and, in severe
cases, results in pre-ignition.
Use of low octane gasoline is one of the most com-
mon causes of detonation. Even with high octane
gasoline, detonation could occur if engine mainte-
nance is neglected.
OTHER CAUSES OF DETONATION
IMPORTANT: Use of improper fuels will cause en-
gine damage and poor performance.
1. Over-advanced ignition timing.
2. Lean fuel mixture at or near full throttle (could be
caused by carburetor or leaking intake manifold).
3. Cross-firing spark plugs.
4. Excess accumulation of deposits on piston and/or
combustion chamber (results in higher compres-
sion ratio).
5. Inadequate cooling of engine by deterioration of
cooling system.
Engine failures, which result from the foregoing con-
ditions, are beyond the control of MerCruiser; there-
fore, no warranty will apply to failures which occur un-
der these conditions.
72425
Detonation Damage
72315
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Страница 1: ...13 Printed in U S A 90 816462 2 695 1995 Brunswick Corporation GM 4 Cylinder MARINE ENGINES ...
Страница 2: ...90 816462 2 695 0 ...
Страница 7: ...1 A IMPORTANT INFORMATION GENERAL INFORMATION 72000 ...
Страница 15: ...1 B 50617 IMPORTANT INFORMATION MAINTENANCE ...
Страница 36: ...1 C IMPORTANT INFORMATION TROUBLESHOOTING ...
Страница 74: ...2 A 50633 REMOVAL AND INSTALLATION 4 CYL ALPHA ONE DRIVE ...
Страница 88: ...3 A 26790 ENGINE 181 CID 3 0L 4 CYLINDER GM ENGINE ...
Страница 137: ...4 A 72079 ELECTRICAL SYSTEMS STARTING SYSTEM ...
Страница 170: ...4 B 71855 ELECTRICAL SYSTEMS IGNITION SYSTEM ...
Страница 197: ...ELECTRICAL SYSTEMS CHARGING SYSTEM 4 C 72078 ...
Страница 237: ...4 D 72747 ELECTRICAL SYSTEMS INSTRUMENTATION ...
Страница 250: ...4 E 72938 ELECTRICAL SYSTEMS WIRING DIAGRAMS ...
Страница 264: ...5 A FUEL SYSTEM FUEL PUMP ...
Страница 271: ...5 B 72681 FUEL SYSTEM MERCARB 2 BARREL CARBURETOR ...
Страница 300: ...6 A 50628 COOLING SYSTEM SEAWATER COOLED MODELS ...
Страница 309: ...6 B 73665 COOLING SYSTEM CLOSED COOLING MODELS ...
Страница 325: ...C 6 EXHAUST SYSTEM MANIFOLD ...
Страница 331: ...7 A 71317 POWER STEERING PUMP ...