Compression Pressure - Yamaha EF2800i Service Manual

COMPRESSION PRESSURE

COMPRESSION PRESSURE
NOTE:
Measure the compression after checking and
adjusting the valve clearance.
1. Warm up the engine for several minutes.
2. Remove:
• Spark plug
3. Connect:
• Compression gauge 1
• Adapter 2
SVU2220
4. Measure:
• Compression
To measure the compression, pull the
recoil starter until the needle stops ris-
ing on the compression gauge.
WARNING
To prevent sparking when cranking the
engine, ground the high-tension cord.
Testing steps (below minimum level):
• Squirt a few drops of oil into the cylinder.
• Measure the compression again.
Reading
If higher than
without oil
If the same as
without oil
2-10
INSP
ADJ
Compression gauge:
YU-33223, 90890-03081
Adapter:
YU-33223-3, 90890-04082
Standard compression pressure:
400 ~ 600 kPa
2
(4 ~ 6 kg/cm , 57 ~ 85 psi)
Diagnosis
• Worn cylinder, piston, and
piston ring
• Defective piston, ring(s),
valve(s), and cylinder
head gasket
• Improper valve timing and
valve clearance