Erratic Idling

FUEL

TROUBLESHOOTING

CAUSE

REMEDY

CARBURETOR

Erratic Idling

1. Incorrect idle needle valve adjustment

1. Adjust needle valves. If unable to improve idling, clean

throttle body. Replace worn needle valves.

2. Carburetor mounting is loose

2. Remove carburetor and governor. Check and replace

gaskets, if necessary. Make sure gaskets are installed

correctly. Tighten mounting nuts securely.

3. Idle tube or air bleed carbonized

3. Disassemble and clean carburetor. Blow carbon from air

bleed orifice and passageway with compressed air.

4. Idle discharge holes gummed or plugged

4. Disassemble and clean carburetor. Blow foreign matter

from the idle discharge holes and the secondary idle air

bleed.

5. Throttle body carbonized or throttle shaft

5. Disassemble and clean throttle body. Remove move

carbon.

6. Incorrect float level

6. Check and adjust float level as necessary.

Replace float if leaking.

7. Worn needle valve and seat

7. Install new needle valve and seat. Adjust float level.

8. Loose throttle body-to-main body screws

8. Install new gasket between main body and throttle body,

if necessary. Tighten throttle body mounting screws.

Carburetor Floods Or Leaks

1. Cracked main body

1. Replace main body. Make sure main body-to-throttle

body screws are tight.

2. Defective body gaskets

2. Replace gaskets. Tighten screws securely.

3. High float level

3. Check and adjust float level.

4. Worn needle valve and seat

4. Clean and check needle valve. If worn, replace valve

and seat. If not worn, check fuel pump pressure.

B-51