Compression Pressure - Yamaha EF2400iS Service Manual

COMPRESSION PRESSURE

4. Connect:
9 Compression gauge 1
9 Adapter 2
SCF2220
5. Measure:
9 Compression
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.
Reading
If higher than
without oil
If the same as
without oil
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
2-13
Compression gauge:
YU-33223, 90890-03081
Adapter:
YU-33223-3, 90890-04082
To measure the compression, pull the
recoil starter until the needle stops ris-
ing on the compression gauge.
Standard compression pressure:
820 ~880 kPa
(8.2 ~8.8 kg/cm
Diagnosis
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
Refer to "COVERS AND FUEL TANK".
Spark plug:
18 Nm (1.8 m · kg, 13 ft · lb)
INSP
ADJ
2 , 119 ~ 128 psi)