TM 5-3740-214-14
Table 5-3. Direct and General Support Maintenance Troubleshooting (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE SKIPS AT HIGH SPEED (Continued)
e.
Start the engine.
(1)
If the engine starts, the problem is solved.
(2)
If the engine does not start, go to Step 2.
Step 2.
Check the carburetor needle valve adjustment.
a.
Adjust the carburetor while it is running.
(1)
Turn the main fuel needle valve to the right (clockwise) until the engine slows down.
(2)
Turn the main fuel needle valve back to the left (counterclockwise) until the engine slows down.
(3)
Turn the main fuel needle valve back to a point halfway between the slow down points.
(4)
If the engine stops skipping, the problem is solved.
(5)
If the engine still skips, go to Step 2b.
CAUTION
BE CAREFUL not to use force when turning the needle valves in and out. Force can damage the valves.
b.
Remove the main fuel needle valve and idle fuel needle valve and check them for damage and/or
plugging.
(1)
If the needle valves are ok, go to Step 2c.
CAUTION
DO NOT use hard metal objects to unplug the needle valves. Hard metal objects will damage them.
(2)
If the needle valves are plugged, unplug them and return them to the carburetor. Go to Step 2d.
(3)
If the needle valves are damaged or cannot be unplugged, replace them and go to Step 2c.
c.
Adjust the needle valves.
(1)
Turn both needle valves all the way to the right (clockwise) until they gently touch bottom.
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