TM 5-3740-214-14
Table 53. Direct and General Support Maintenance Troubleshooting (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE OPERATES ERRATICALLY (Continued)
(5)
Return the carburetor to the engine and go to Step llf. Make sure the carburetor to manifold
gasket seals well.
f.
Start the engine.
(1)
If the engine starts, the problem is solved. Go to Step 8g.
(2)
If the engine does not start, go to Step 9.
g.
Adjust the carburetor while the engine 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 the right to a position half-way between the slow down
points.
Step 9.
Check the engine compression.
NOTE
Because automatic compression release engines release compression at
600 rpm, there is a different compression test procedure for this engine.
a.
Start the engine and run it for fifteen minutes.
b.
Shut the engine OFF and remove the spark plug.
CAUTION
BE CAREFUL when removing the spark plug. Too much force can break the Insulator.
(1)
Loosen the spark plug a few turns.
(2)
Blow out the spark plug well with high pressure air. This will clean out any dirt or debris that can
fall into the cylinder.
(3)
Remove the spark plug by hand. /
c.
Place a compression gage in the spark plug hole. Make sure it seals well.
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