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CHK
ADJ
MEASURING THE COMPRESSION PRESSURE
CAUTION:
3. Disconnect:
Sspark plug cap
4. Remove:
Sspark plug
Before removing the spark plugs, use com-
pressed air to blow away any dirt accumu-
lated in the spark plug wells to prevent it
from falling into the cylinders.
5. Install:
Scompression gauge
1
Sadapter
2
Compression gauge
90890-03081
Adapter
90890-04082
6. Measure:
Scompression pressure
Above the maximum pressure ! Inspect the
cylinder head, valve surfaces, and piston
crown for carbon deposits.
Below the minimum pressure ! Squirt a few
drops of oil into the affected cylinder and
measure again.
SRefer to the following table.
Compression pressure
(With oil applied into cylinder)
Reading Diagnosis
Higher than
without oil
Piston wear or damage
! Repair.
Same as
without oil
Piston ring(-s), valves, cyl-
inder head gasket
or piston possibly defec-
tive ! Repair.
Compression pressure (at
sea level)
Compression pressure (at sea lev-
el):
Standard:
1,050 kPa (10.5 kg/cm
2
,
10.5 bar)/400 r/min.
Minimum:
900 kPa (9.0 kg/cm
2
,
9.0 bar)/400 r/min.
Maximum:
1,200 kPa (12.0 kg/cm
2
,
12.0 bar)/400 r/min.