| Condition | Possible Cause | Action |
|---|---|---|
|
Engine noise
NOTE:
Before checking the mechanical noise, make sure that:
•
Ignition timing is properly adjusted.
• Specified spark plug is used. • Specified fuel is used. |
Improper valve lash
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Worn valve stem and guide
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Weak or broken valve spring
|
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Warped or bent valve
|
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Loose camshaft housing bolts
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Worn piston, ring and cylinder bore
|
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Worn crank pin bearing
|
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Worn crank pin
|
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Loose connecting rod nuts
|
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Low oil pressure
|
Condition “Low Oil Pressure”
|
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Worn crankshaft journal bearing
|
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Worn crankshaft journal
|
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Loose lower crankcase (bearing cap) bolts
|
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Excessive crankshaft thrust play
|