2-13
COMPRESSION PRESSURE
SCF2220
4. Connect:
9
Compression gauge
1
9
Adapter
2
5. Measure:
9
Compression
To measure the compression, pull the
recoil starter until the needle stops ris-
ing on the compression gauge.
w
To prevent sparking when cranking the
engine, ground the high-tension cord.
Testing steps (below minimum level):
9
Squirt a few drops of oil into the cylinder.
9
Measure the compression again.
Testing steps (above maximum level):
9
Check the cylinder head, valve surfaces,
and piston crown for carbon deposits.
6. Install:
9
Spark plug
9
Rear cover
Refer to “COVERS AND FUEL TANK”.
INSP
ADJ
Compression gauge:
YU-33223, 90890-03081
Adapter:
YU-33223-3, 90890-04082
Standard compression pressure:
820 ~880 kPa
(8.2 ~8.8 kg/cm
2
, 119 ~ 128 psi)
Reading
Diagnosis
If higher than
without oil
If the same as
without oil
9
Worn cylinder, piston, and
piston ring
9
Defective piston, ring(s),
valve(s), and cylinder head
gasket
9
Improper valve timing and
valve clearance
Spark plug:
18 Nm (1.8 m · kg, 13 ft · lb)
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