TM 5-3740-214-14
Table 5-3. Direct and General Support Maintenance Troubleshooting (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE OPERATES ERRATICALLY (Continued)
Figure 5-167. Choke Open Position
d.
Set the choke wide open. Remove the air cleaner if necessary.
e.
Crank the engine by hand counterclockwise (left: opposite to normal rotation).
f.
Take eight to ten compression readings.
(1)
The first few turns of the engine, the compression may be as low as 30 psi. After the seventh
turn, the compression should be 90 psi.
(2)
If the compression is less than 90 psi, replace the engine.
8.
ENGINE KNOCKS
Step 1.
Check the fuel octane rating.
a.
If the octane rating is below 90, change the fuel supply.
b.
If the octane rating is 90 or above, go to Step 2.
Step 2.
Check the breaker points.
5-152
