Honda CRF50F 2004-2015 - Troubleshooting

CYLINDER HEADIV ALVES
TROUBLESHOOTING
• Engine top-end problems usually affect engine performance . These problem can be diagnosed by a compression test or
bV tracing engine noises to the top-end with a sounding rod stethoscope .
• If the perfo r mance 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 8-5).
Compression too low, hard starting or poor performance at l ow speed
• Valves:
- Incorrect valve clearance
-
Burned or benl 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 8·5)
Comp ression t oo high . overheating or knocking
• Excessive carbon build-up on pis ton cr own or on combustion chamber
Excessive smoke
• Cylinder head:
-
Worn valve stem or valve guide
- Damaged stem seal
•
Worn cylinder , piston or piston ri ngs (page 8-5)
Ex cessive nois e
• Cylinder head:
-
Incorrect valve clearance
- 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 (page 10-7)
- Worn cam sprocket teeth
-
Worn rocker arm and/ or shaft
• Worn cylinder , piston or piston rings (page 8·5)
Rough idle
• Low cylinder compression
7-5