Eton VIPER 70, Service Manual

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5. CYLINDER HEAD / VALVES
5.1 SERVICE / GENERAL INFORMATION
This section describes cylinder head, valves, camshaft and the other parts
maintenance.
The engine must be removed from the frame to service cylinder head.
Camshaft lubrication oil is fed to the cylinder head through an oil KROH in the
engine case.
Before installing the cylinder head make sure the KROH is not clogged and the
gasket, O-ring and dowel pins are in place.
5.1 SERVICE / GENERAL INFORMATION
5.4 CYLINDER HEAD REMOVAL
5.2 TROUBLESHOOTING 5.5 CYLINDER HEAD ASSEMBLY
5.3 CAMSHAFT COMPOSITION
5.2 TROUBLESHOOTING
Engine top-end problems usually affect engine performance. These problems
can be diagnosed by a compression test, or by tracing engine noise to the top
end with a sounding rod or stethoscope.
Low compression
Valve
Incorrect valve adjustment.
Worn or damaged valve seats.
Burned or bent valve.
Incorrect valve timing.
Weak valve spring.
Cylinder head
Leaking or damaged head gasket.
Warped or cracked cylinder head.
Faulty cylinder or piston.
Excessive noise
Incorrect valve adjustment.
Sticking valve or broken valve spring.
Worn or damaged rocker arm or camshaft.
Worn or damaged cam chain.
Worn or damaged cam chain tension.
Worn cam sprocket teeth.
Excessive smoke
Damaged valve stem seal.
Faulty cylinder or piston rings.