TM 5-3740-214-14
Table 4-3. Troubleshooting Chart (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE OVERHEATS (Continued)
CAUTION
DO NOT use force to turn the needle valve in.
a. Turn main fuel needle valve all the way in to gently touch the bottom.
b. Turn main fuel needle valve to the left (counterclockwise) two full turns.
c. Go to Step 5.
Step 5. Start engine and adjust main fuel needle valve.
a. Turn main fuel needle valve to the right (counterclockwise) until the engine slows
down.
b. Turn main fuel needle valve to the left (clockwise) until it slows down.
c. Turn main fuel needle valve back to a point halfway between the slow down
points.
d. Allow engine to run for 15 minutes.
(1) If engine dows not overheat, the problem is solved.
(2) If engine still overheats, replace it. The problem is internal, notify your
supervisor.
8. ENGINE BACKFIRES
Figure 4-63. Carburetor
Step 1. Readjust main fuel needle valve on carburetor while engine is running.
a. Turn main fuel needle valve to the right (clockwise) until the engine slows down.
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