Linhai HY510S Service Manual page 160

CHAPTER 3 ENGINE
3.8. Troubleshooting
Complaint
Poor engine
running in
high-speed range.
Exhaust smoke is
dirty or thick
Engine lacks
power
Engine
overheats
Symptom and Possible Causes
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
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
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
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 (→16-5)
LH500ATV-D SERVICE MANUAL14.0
Remedy
Replace
Replace
Clean or replace
Adjust or replace
Replace
Adjust float chamber fuel level
Clean or replace
Clean
Clean
Clean
Check oil level and drain
Replace
Replace
Replace
Replace
Replace
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
Clean
Check level, add or drain
Replace
Clean
Adjust fuel level
Tighten or replace
Change engine oil
CHAPTER 3 ENGINE PAGE. 3- 129