Yamaha XV1600A1999 Service Manual page 84

MEASURING THE COMPRESSION PRESSURE
8. Install:
S compression gauge 1
S compression gauge adapter 2
Compression gauge
90890-03081
Compression gauge adapter
90890-04082
9. Measure:
S compression pressure
Out of specification ! Refer to steps (c) and
(d).
Compression pressure (at sea
level)
Minimum
1,000 kPa (10 kg/cm
Standard
1,200 kPa (12 kg/cm
Maximum
1,400 kPa (14 kg/cm
a. Set the main switch to "ON".
b. With the throttle wide open, crank the engine
until the reading on the compression gauge
stabilizes.
WARNING
To prevent sparking, ground all spark plug
leads before cranking the engine.
NOTE:
The difference in compression pressure be-
tween cylinders should not exceed 100 kPa (1
2
kg/cm ).
c. If the compression pressure is above the
maximum specification, check the cylinder
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 measure again.
3-18
CHK
ADJ
2
)
2
)
2
)