TM 5-3740-214-14
Table 5-3. Direct and General Support Maintenance Troubleshooting (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE LACKS POWER (Continued)
c.
Check the switch with a volt-ohmmeter. Place the positive probe (+) on the battery side of the switch
and the negative probe on the engine side of the switch.
(1)
If the switch is ok, go to Step 5.
(2)
If the switch is not ok, replace it and go to Step 4a.
Step 5.
Make sure there is spark to the spark plug.
a.
Make sure the ignition switch is turned OFF.
b.
Remove the spark plug wire from the spark plug.
c.
Turn the ignition switch ON.
WARNING
DO NOT hold the spark plug wire in your bare hands while testing for spark. You can be severely
shocked.
Figure 5-125. Spark Test
d.
Hold the spark plug wire about 3/16 inch (4.76 mm) from a grounded engine part.
e.
Crank the engine over. As the points open and close, a spark should jump between the spark plug wire
and the engine.
(1)
If there is a bright blue spark, go to Step 6.
(2)
If there is no spark or the spark is weak and yellow, go to Step 7.
Step 6.
Check the spark plug.
CAUTION
BE CAREFUL when removing the spark plug from the engine. The insulator will break easily.
5-116
