Compression Pressure Measurement - PGO G-MAX 50 Service Manual

(6)Compression pressure measurement:

1.Measure it when the engine is warm.
2.Remove the cover.
3.Remove spark plug then place compression pressure gauge.
4.Fully open the throttle, and using starting motor 5 seconds continuously, measure the
compression pressure.
5.Compression pressure:
50cc: 6 kg/c ㎡ @600rpm
125cc: 12 kg/c ㎡ @750rpm
150/200/220 cc: 11 kg/c ㎡ @650rpm
250 cc: see engine chapter
6.when the compression pressure is too low, check the following:
a. cylinder head gasket cracked.
b. piston cylinder worn out.
c. piston ring worn out.
7.If the compression pressure is too high it may be due to the carbon piled up on combustion
chamber and piston tip.