Yamaha YZF-R1S Service Manual page 102

MEASURING THE COMPRESSION PRESSURE
4. Install:
S compression gauge 1
S adapter
Compression gauge
90890-03081, YU-33223
Adapter
90890-04136
5. Measure:
S compression pressure
Out of specification ! Refer to steps (c) and
(d).
Compression pressure
(at sea level)
Minimum
1,290 kPa (12.90 kg/cm
12.90 bar, 183.48 psi)
Standard
1,480 kPa (14.80 kg/cm
14.80 bar, 210.5 psi)
Maximum
1,660 kPa (16.60 kg/cm
16.60 bar, 236.11 psi)
a. Turn 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 , 1 bar, 14.22 psi).
c. If the compression pressure is above the
maximum specification, check the cylinder
head, valve surfaces and piston crown for
carbon deposits.
Carbon deposits ! Eliminate.
3-25
CHK
ADJ
2
,
2
,
2
,