51
2
、
Gradual acceleration of engine rotation speed
→No speed change→
1. Bad performance of fuel supplying
Normal acceleration of engine rotation speed
2. Air filter blocked
3. Ventilation hole on carburetor cover
blocked
4. Muffler exhaust blocked
3
、
Check ignition timing
→Wrong ignition switch→ 1
、
CDI damaged
Correct ignition timing 2
、
Magneto failed
3
、
Pulse generator
4
、
Check valve clearance
→Incorrect clearance→ 1
、
Incorrect adjustment for valve clearance
Correct valve clearance 2
、
Valve seat abrasion
5
、
Check cylinder pressure
→Low pressure→ 1
、
Narrow valve clearance
Normal pressure 2
、
Valve distorted or seized up
3
、
Abrasion of valve seat
4
、
Abrasion of cylinder and piston
rings
5
、
Damage on cylinder gasket
6
、
Incorrect timing of gas distribution
7
、
Incorrect installation of spark plug
out of position
6
、
Check carburetor
→Carburetor blocked→ 1
、
Dirty fuel
Carburetor without blocking 2
、
Carburetor without periodic washing
7
、
Check spark plug
→Carbon buildup and incorrect color→ 1
、
No periodic maintenance was made
Normal spark plug 2
、
Incorrect heat value of spark plug
3
、
Too narrow the clearance between
spark plug and electrode
8
、
Check oil through view windown
→Incorrect oil Quantity→ 1
、
Too high the oil level
Normal oil quantity 2
、
Too low the oil level
3
、
Dirty oil
9
、
Remove cylinder head cover, check lubricant 1
、
Oil tube blocked
of valve
→Abnormal valve lubrication→ 2
、
Abnormal working of oil pump
Normal valve lubrication
10
、
Check overheating of engine
→Overheated→ 1
、
Carbon buildup in combustion chamber
Without overheating 2
、
Used fuel without meeting demands
3
、
Clutch skidding
4
、
excessive rich of mixed gas
5
、
excessive amount of oil
11
、
Driving in high speed
→Detonation of engine→ 1
、
Abrasion on cylinder and piston
No detonation 2
、
Carbon in combustion chamber
3
、
Fuel failed meet specification
4
、
Too much advancing before ignition timing