Honda CRF50F 2004-2015 Service Manual page 205

TROUBLESHOOTING
16-4
8. Spark Plug Inspection
Remove and inspect the spark plug.
Is the spark plug in good condition?
NO _ . Plug not serviced frequently enough
• Incorrect spark plug heat range
YES - GO TO STEP 9.
9. Engine Oillnspeetion
Check the oil level and condition.
Is the engine oil in good condition?
NO _ . Oil level too high
• Oil level too low
• Contaminated oil
YES - GO TO STEP 10.
10. lubrication Inspection
Remove cylinder head cover and inspect lubrication.
Is the valve train lubricated properly?
NO _ . Clogged oil passage
• Clogged oil control orifice
YES - GOTDSTEP1' .
11 . Over Heating Inspection
Check for engine over heating.
Is
the engine over heating?
YES _ . Excessive carbon build-up in combustion chamber
• Use of poor quality fuel
• Clutch slipping
• lean fu el mixture
• Wrong type of fue l
NO - GOTO STEP 12.
12. Engine Knocking Inspection
Accelerate or run at high speed.
Does the engine knock?
YES _. Worn piston and cylinder
• Wrong type of fuel
• Excessive carbon build-up in com bustion chamber
• Ignition timing too advanced (faulty ignition contro l module)
• lean fuel mixtu re