Cylinder Head/Valve/Camshaft Troubleshooting; Compression Too Low; Compression Too High; Excessive Smoke - Honda Fourtrax Rancher AT 2004 Service Manual

CYLINDER HEADIV ALVEI CAMSHAFT
TROUBLESHOOTING
• Engine top-end problems usually affect engine performance. These can be diagnosed by a compression test, or by trac-
ing top-end noise with a sounding rod or stethoscope.
,. If the performance is poor at low speeds, check for a white smoke in the crankcase breather hose. If the hose is smoky,
check for seized piston ring (page 9-2).
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
- Valve stuck open
• Cylinder head:
- Leaking or damaged cylinder head gasket
- Loose spark plug
- Warped or cracked cylinder head
• Cylinderfpiston problem (page 9-3)
Compression too high. overheating or knocking
• Excessive carbon build-up on piston head or combustion chamber
• Worn or damaged decompressor system
Excessive smoke
• Worn valve stem or valve guide
• Damaged stem seal
• Cylinder/piston problem (page 9-3)
Excessive noise
• Incorrect valve clearance
• Sticking valve or broken valve spring
• Excessively worn valve seat
• Worn or damaged camshaft
• Worn rocker arm andlor shaft
• Worn rocker arm follower or valve stem end
• Worn or damaged push rod andlor cam follower
• Worn cam chain
• Worn or damaged cam chain tensioner
• Worn cam sprocket teeth
• Cylinder/piston problem (page 9-3)
Rough idle
• low cylinder compression
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