Table 5-3. Direct and General Support Maintenance Troubleshooting (Continued)
TEST OR INSPECTION
ENGINE KNOCKS (Continued)
If the compression is mutch greater than 100 psi, there may be carbon build-up in the cylinder.
Remove the cylinder head and check for carbon build-up.
If there is carbon build-up, replace the engine.
ENGINE SKIPS AT HIGH SPEED
Check the spark plug.
BE CAREFUL when removing the spark plug from the engine. The insulator will break easily.
Remove the spark plug.
Figure 5-173. Spark Plug Cleaning and Removal
Loosen the spark plug a few turns.
Blow high pressure air into the spark plug well. This will clean out any dirt or debris.
Remove the spark plug by hand.
Check the spark plug visually. Replace it and go to Step Id, if there are:
Cracks in the insulator.