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SECTION 6B
FUEL SYSTEMS
Troubleshooting
Make sure the carburetor is securely fastened to
the engine using gaskets in good condition.
If engine troubles are experienced that appear to be
fuel system related, check the following areas before
adjusting or disassembling the carburetor.
© Make sure the fuel tank is filled with clean, fresh
gasoline.
* Make sure the fuel tank cap vent is not blocked
and that it is operating properly.
* Make sure fuel is reaching the carburetor. This
includes checking the fuel shut-off valve, fuel tank
filter screen, in-line fuel filter, fuel lines, and fuel
e Make sure the air cleaner element is clean and all
air cleaner components are fastened securely.
* Make sure the ignition system, governor system,
exhaust system, and throttle and choke controls
are operating properly.
If, after checking the items listed above, starting prob-
lems or other conditions similar to those listed in the
following table exist, it may be necessary to adjust or
service the carburetor.
pump for restrictions or faulty components.
Condition
Possible Cause/Probable Remedy
1. Engine starts hard, or runs roughly or
1. Idle fuel mixture or idle speed are improperly adjusted. Adjust the idle
q
Stalls at idle speed.
speed screw, then adjust idle fue! needle.
. Engine runs rich. (indicated by black, | 2a. Choke
Гу closed during operation. Check the choke lever and linl
'sooty exhaust smoke, misfiring, loss of
age to ensure choke is opening after warm-up.
speed and power, governor hunting, ог | b, Idle and/or main fuel mixture improperly adjusted. Adjust idle and/or main
excessive throttle opening.)
fuel needle.
C. Float level set too high. With fuel bowl removed and carburetor inverted,
set exposed surface of float parallel with the bowl gasket surface of carbu-
retor body.
d. Dirt under fuel inlet needle. Remove needle. Clean needle and seat and
blow with compressed air.
е. Bowl vent or air bleeds plugged. Remove fuel bowl, idle fuel adjusting
needle, and welch plugs. Clean vent, ports, and air bleeds. Blow out all
passages with compressed air.
f. Fuel bowl gasket leaks. Remove fuel bowl and replace gasket.
g. Leaky, cracked, or damaged float. Submerge float to check for leaks.
3. Engine runs lean. (Indicated by misfir- | 3a. Idie and/or main fuel mixture improperly adjusted. Adjust idle and/or main
ing, loss of speed and power, governor
fuel needle.
hunting, or excessive throttle opening.) | р. Ficat level set too low. With fue! bowl removed and carburetor inverted, set
exposed surface of float parallel with the bow! gasket surface of carburetor
body.
c. idle holes plugged: dirt in fuel delivery channels. Remove fuel bowl, idle
fuel adjusting needie, main fuel jet, and welch plugs. Clean all passages
and blow out with compressed air.
4. Fuel leaks from carburetor.
4a. Float level set too high. See Remedy 2c.
b. Dirt under fue! inlet needle. See Remedy 2d.
C. Bowl vent plugged. Remove fuel bowl and clean bow! vent. Biow out with
compressed air.
d. Float is cracked or damaged. Replace float.
е. Bowl retaining screw gasket damaged. Replace gasket.
f. Bowi retaining screw is not tightened. Torque screw to
6B.3
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