CF MOTO CF500-5, Service Manual

Page: 252 / 254

14 Troubleshooting
14 14
14 14
14
14-7
Complaint Symptom and Possible Causes Remedy
Poor engine
running in
high-speed
range.
1. Week valve spring
2. Worn
camshaft
3. Fouled spark plug
4. Insufficient spark plug gap
5. Improper
valve timing
6. Faulty ignition coil
7. Low fuel level in float chamber
8. Dirty air filter
9. Clogged fuel hose, resulting in
poor fuel supply
10. Clogged fuel valve
Replace
Replace
Clean or replace
Adjust or replace
Replace
Adjust float chamber fuel level
Clean or replace
Clean
Clean
Clean
Exhaust smoke
is dirty or thick
1. Excessive engine oil
2. Worn piston ring
3. Worn valve guide
4. Scored or scuffed cylinder wall
5. Worn valve stem
6. Worn valve stem oil seal Check oil level and drain
Replace
Replace
Replace
Replace
Replace
Engine lacks
power
1. Improper valve clearance
2. Weak valve spring
3. Improper
valve timing
4. Worn cylinder
5. Worn piston ring
6. Improper
valve seating
7. Fouled spark plug
8. Improper spark plug gap
9. Clogged carburetor jet
10.
Improper fuel level in fuel
chamber
11. Dirty air filter
12. Worn rocker arm or rocker arm
shaft
13. Air leakage from air intake pipe
14. Excessive engine oil
Adjust
Adjust
Adjust
Replace
Replace
Replace or Correct
Clean or replace
Clean or replace
Clean or replace
Adjust fuel level
Clean or replace
Replace
Tighten or replace
Check oil level and drain
Engine
overheats
1. Carbon deposit on piston top
2. Insufficient or excessive engine
oil
3. Faulty oil pump
4. Clogged
oil passage
5. Fuel level in float chamber is too
low
6. Air leakage from air intake pipe
7. Incorrect engine oil
8. Faulty cooling system
Clean
Check level, add or drain
Replace
Clean
Adjust fuel level
Tighten or replace
Change engine oil