5.4
Section 5
Fuel System and Governor
Troubleshooting - Gasoline Systems
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 fi lled 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
fi lter screen, in-line fuel fi lter, fuel lines, and fuel
pump for restrictions or faulty components as
necessary.
Troubleshooting - Gasoline Fuel Systems Carburetor
Condition
Possible Cause/Probable Remedy
1. Low idle fuel mixture/speed improperly adjusted. Adjust the low
idle speed screw, then adjust the low idle fuel needle.
1. Engine starts hard, runs roughly
or stalls at idle speed.
2. Engine runs rich. (Indicated by
black, sooty exhaust smoke,
misfi ring, loss of speed and power,
governor hunting, or excessive
throttle opening).
2a. Choke partially closed during operation. Check the choke lever/
linkage to ensure choke is operating properly.
b. Low idle fuel mixture is improperly adjusted. Adjust low idle fuel
needle.
c. Float level is set too high. With fuel bowl removed and carburetor
inverted, the exposed surface of fl oat must be parallel with the
bowl gasket surface of the carburetor body.
d. Dirt under fuel inlet needle. Remove needle; clean needle and
seat and blow with compressed air.
e. Bowl vent or air bleeds plugged. Remove fuel bowl, low 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 fl oat. Submerge fl oat to check for
leaks.
3. Engine runs lean. (Indicated by
misfi ring, loss of speed and power,
governor hunting, or excessive
throttle opening).
3a. Low idle fuel mixture is improperly adjusted. Adjust low idle fuel
needle.
b. Float level is set too low. With fuel bowl removed and carburetor
inverted, the exposed surface of fl oat must be parallel with the
bowl gasket surface of the carburetor body.
c. Idle holes plugged; dirt in fuel delivery channels. Remove fuel
bowl, low idle fuel adjusting needle, and welch plugs. Clean main
fuel jet and all passages; blow out with compressed air.
4. Fuel leaks from carburetor.
4a. Float level set too high. See Remedy 2c.
b. Dirt under fuel inlet needle. See Remedy 2d.
c. Bowl vent plugged. Remove fuel bowl and clean bowl vent. Blow
out with compressed air.
d. Float is cracked or damaged. Replace fl oat.
e. Bowl retaining screw gasket damaged. Replace gasket.
f. Bowl retaining screw loose. Torque screw to specifi cations.
• Make sure the air cleaner base and carburetor
are securely fastened to the engine using gaskets
in good condition.
• 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
problems or conditions similar to those listed in the
following table exist, it may be necessary to adjust or
service the carburetor.
Summary of Contents for CV11-16
Page 1: ...1 SERVICE MANUAL VERTICAL CRANKSHAFT CV11 16 CV460 465 CV490 495...
Page 2: ......
Page 4: ......
Page 22: ...2 4 Section 2 Special Tools...
Page 30: ...4 4 Section 4 Air Cleaner and Air Intake System...
Page 56: ...6 6 Section 6 Lubrication System...
Page 112: ...9 16 Section 9 Disassembly...
Page 148: ...11 24 Section 11 Reassembly...
Page 149: ......