DAELIM VJF125 Service Manual - page 274

21-3

TROUBLESHOOTING

POOR PERFORMANCE (AT LOW AND IDLE SPEED)

INSPECTION

CAUSE OF TROUBLE

Not contaminated or not

discolored.

Contaminated or

discolored

Lean fuel mixture.

Using spark plug with on incorrect heat

range.

9. Check the spark plug.

Level normal

Level low or high

Oil level too high.

Oil level too low.

Contaminated oil.

10. Check oil level.

Valve train lubricated properly.

Valve train lubricated

improperly.

Oil level too low.

Contaminated oil.

Faulty oil pump.

Clogged oil passage.

11. Remove cylinder head

30mm hole cap, and inspect

lubrication.

Not overheated.

Overheated

Excessive carbon build-up in combustion

chamber.

Poor quality fuel being used.

Lean fuel mixture.

Clutch slipping.

12. Check for engine overheating.

Correct

Incorrect

Incorrect valve clearance.

Faulty ECU unit.

Faulty pulse generator.

1. Check ignition timing and

valve clearance.

No leak

Leaking

Faulty insulator O-ring.

Loose throttlebody.

2. Check inlet pipe for leakage.

Sparks normal.

Weak or intermittent

sparks

Carbon depasited on spark plug or spark

plug contaminated.

3. Check sparks.

Engine does not knocking.

Engine knocking

Worn piston ring and cylinder.

Lean fuel mixture.

Excessive carbon build-up in cambustion

chamber.

Incorrect ignition timing.

13. Accelerate or run at high

speed.

INSPECTION

CAUSE OF TROUBLE