Fuel System
23
32 690 01 Rev. D
KohlerEngines.com
Troubleshooting-Carburetor Related Causes
Condition
Possible Cause
Conclusion
Engine starts hard, runs rough, or
stalls at idle speed.
Low idle fuel mixture (some models)/
speed improperly adjusted.
Adjust low idle speed tab, then adjust
low idle fuel needle.
Engine runs rich (indicated by black,
sooty exhaust smoke, misfiring, loss
of speed and power, governor
hunting, or excessive throttle
opening).
Clogged air cleaner.
Clean or replace air cleaner.
Choke partially closed during
operation.
Check choke lever/linkage to ensure
choke is operating properly.
Low idle fuel mixture is improperly
adjusted.
Adjust low idle fuel needle (some
models).
Float level is set too high.
Separate carburetor air horn from
carburetor body, adjust float
according to steps outlined in repair
kit installation instructions.
Dirt under fuel inlet needle.
Remove needle; clean needle and
seat and blow with compressed air.
Bowl vent or air bleeds plugged.
Remove low idle fuel adjusting
needle. Clean vent, ports, and air
bleeds. Blow out all passages with
compressed air.
Leaky, cracked, or damaged float.
Submerge float to check for leaks.
Engine runs lean (indicated by
misfiring, loss of speed and power,
governor hunting, or excessive
throttle opening).
Low idle fuel mixture is improperly
adjusted.
Adjust low idle fuel needle (some
models).
Float level is set too low.
Separate carburetor air horn from
carburetor body, adjust float
according to steps outlined in repair
kit installation instructions.
Idle holes plugged; dirt in fuel delivery
channels.
Remove low idle fuel adjusting
needle. Clean main fuel jet and all
passages; blow out with compressed
air.
Fuel leaks from carburetor.
Float level set too high.
Adjust float according to repair kit
installation instructions.
Dirt under fuel inlet needle.
Remove needle; clean needle and
seat and blow with compressed air.
Bowl vents plugged.
Blow out with compressed air.
Carburetor bowl gasket leaks.
Replace gasket.