Table 5-1. Direct and General Support Preventive Maintenance Checks and Services (Continued)
M = Monthly
A/R = As Required
Q = Quarterly
H = Hourly
ITEM TO BE INSPECTED
NO. M A/R
ENGINE ASSEMBLY (Continued)
Figure 5-4. Spark Plug Cleaning
Shutoff engine and remove spark plug.
BE CAREFUL when removing spark plug. Too much force can break
spark plug insulator.
(a) Loosen spark plug a few turns.
(b) Blow dirt out of spark plug well with high pressure air.
(c) Remove spark plug by hand.
Install compression gage in spark plug hole. Make sure it seals well.
Set choke wide open. Remove air cleaner if necessary.
Remove belt guard and crank engine by hand counterclockwise (left: opposite
normal rotation). Turn engine over about eight times.
(a) With the first few turns the compression may be as low as 30 psi. After
the seventh turn, the compression should be 90 psi.