ARMY TM 9-2805-257-14
AIR FORCE TO 38G2-103-2
NAVY NAVFAC P-8-612-14E
5-24. Compression Test.
This task covers:
General Mechanics Tool Kit (Item 1, Appendix B)
Tester, Cylinder Compression (NSN 4910-00-250-2423)
(Item 2, Appendix B)
This engine is equipped with two cylinders, the procedures for compression test is the
same for both.
Test. (figure 5-25)
Disconnect ignition cable (1) from spark plug (2).
Remove spark plug (2) from engine (3).
Install suitable pressure gage (4) in spark plug hole.
Using starter rope crank engine several times, and check pressure gage.
As altitude increases cylinder compression will decrease.
Cylinder compression should be a minimum of 90 psi (63279 kpa) at sea level.
Remove pressure gage (4).
Install spark plug (2), and connect ignition cable (1).