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CHK
ADJ
MEASURING THE COMPRESSION PRESSURE
8. Install:
• compression gauge 1
• compression gauge adapter 2
Compression gauge
YU-33223
Compression gauge adapter
YU-33223-3
9. Measure:
• compression pressure
Out of specification
→ Refer to steps (c)
and (d).
▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼
a. Set the main switch to “ON”.
b. With the throttle wide open, crank the
engine until the reading on the compres-
sion gauge stabilizes.
WARNING
WARNING
To prevent sparking, ground all spark plug
leads before cranking the engine.
NOTE:
The difference in compression pressure
between cylinders should not exceed
100 kPa (1 kg/cm
2
, 14 psi).
c. If the compression pressure is above the
maximum specification, check the cylin-
der head, valve surfaces, and piston
crown for carbon deposits.
d. Carbon deposits
→ Eliminate.
e. If the compression pressure is below the
minimum specification, squirt a few
drops of oil into the cylinder and mea-
sure again.
Compression pressure (at sea
level)
Minimum
1,000 kPa (10 kg/cm
2
, 142 psi)
Standard
1,200 kPa (12 kg/cm
2
, 171 psi)
Maximum
1,400 kPa (14 kg/cm
2
, 199 psi)
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