CYLINDER HEAD/VALVES
8-5
TROUBLESHOOTING
• Engine top-end problems usually affect engine performance. These problem can be diagnosed by a compression test or
by tracing engine noises to the top-end with a sounding rod stethoscope.
• If the performance is poor at low speeds, check for white smoke in the crankcase breather hose. If the hose is smoky,
check for a seized piston ring (page 12-15).
Compression too low, hard starting or poor performance at low speed
• Valves:
– Incorrect valve adjustment
– Burned or bent valve
– Incorrect valve timing
– Broken valve spring
– Uneven valve seating
• Cylinder head:
– Leaking or damaged head gasket
– Warped or cracked cylinder head
• Worn cylinder, piston or piston rings (page 12-15)
Compression too high, overheating or knocking
• Excessive carbon build-up on piston crown or on combustion chamber
Excessive smoke
• Cylinder head:
– Worn valve stem or valve guide
– Damaged stem seal
• Worn cylinder, piston or piston rings (page 12-15)
Excessive noise
• Cylinder head:
– Incorrect valve adjustment
– Sticking valve or broken valve spring
– Damaged or worn camshaft
– Loose or worn cam chain
– Worn or damaged cam chain
– Worn or damaged cam chain tensioner
– Worn cam sprocket teeth
• Worn cylinder, piston or piston rings (page 12-15)
Rough idle
• Low cylinder compression
Interior cutter, 30 mm (60° IN)
07780-0014000
or equivalent commercially avail-
able.
Interior cutter, 24 mm (60° EX)
070PH-Z0D0100
or equivalent commercially avail-
able.
Manuals by Motomatrix / www.motomatrix.co.uk / The Solution For Lost Motorcycle Coded Keys.
email: info@motomatrix.co.uk
To Next Page
