6. Cylinder Head/Valve
6-3
Troubleshooting
Engine performance will be effected by troubles on engine top-end. The troubles usually can be
determinated or by performing cylinder compression test and judging the abnormal noise generated.
Rough Idle
•
Low compression pressure
Low compression pressure
1. Valve
z
Improper valve adjustment
z
Burnt or bended valve
z
Improper valve timing
z
Valve spring damaged
z
Valve carbon
z
Poor sealing on valve seat
z
Improper spark plug installation
2. Cylinder head
z
Cylinder head gasket leaking or damage
z
Tilt or crack cylinder surface
3. Piston
z
Piston ring worn out
High compression pressure
•
Too much carbon deposit on combustion chamber or piston head
Noise
•
Improper valve clearance adjustment
•
Burnt valve or damaged valve spring
•
Camshaft wear out or damage
•
Cam chain wear out or looseness
•
Auto-tensioner wear out or damage of cam chain
•
Camshaft sprocket wear out
•
Rocker arm or rocker arm shaft wear out
White smoke
•
Valve guide or valve stem wear out
•
Valve stem seal wear out
