DAELIM VJF125 Service Manual - 21. Troubleshooting

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21. TROUBLESHOOTING

ENGINE WON’T START 

OR IS HARD TO START

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ENGINE LACKS POWER

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POOR PERFORMANCE 

(AT LOW AND IDLE SPEED)

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POOR PERFORMANCE

(AT  HIGH SPEED)

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ENGINE WON’T START OR IS HARD TO START

1. Check fuel flow to carburetor.

Fuel not supplied

Fuel tank empty.

to the carburetor

Clogged fuel tube or fuel filter.

Sticking float valve.

Clogged fuel tank cap hole.

2. Check the spark plug.

Weak or no

Faulty spark plug.

spark

Contaminated spark plug.

Disconnected or shorted high tension wires.

Faulty pulse generator.

Faulty main switch.

3. Test cylinder compression.

Low compression

Low speed of starter crank.

Incorrect valve clearance.

Faulty valve seat.

Worn cylinder and piston rings.

Seized valve.

Improper valve timing.

4. Start by following normal

Engine starts

Improper chock valve operation.

procedure.

but stops.

Improper chock cable free play.

Carburetor incorrectly adjusted.

Improper ignition timing.

Fuel contaminated.

Lean fuel mixture.

5. Remove and inspect spark plug.

Wet plug

Carburetor flooded.

Throttle valve open.

Choke closed.

Air cleaner dirty.

Rich fuel mixture.

Fuel is supplied

Good spark

Compression normal

Engine does not start.

Dry plug

INSPECTION

CAUSE OF TROUBLE

6. Close  the  choke  and  start

engine again.

POOR HANDLING

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POOR FRONT/REAR SUSPENSION

PERFORMANCE

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FUEL GAUGE

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