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
Improper valve adjustment
Burnt or bended valve
Improper valve timing
Valve spring damaged
Valve carbon
Poor sealing on valve seat
Improper spark plug installation
2. Cylinder head
Cylinder head gasket leaking or damage
Tilt or crack cylinder surface
3. Piston
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
This chapter Contents
6. Cylinder Head/Valve
6-3