Yamaha XVS250 2001 Service Manual page 75

MEASURING THE COMPRESSION PRESSURE
Refer to the following table.
Compression pressure
(with oil applied into cylinder)
Reading
Higher than
without oil
Same as
without oil
Compression pressure (at sea
level):
Standard:
1,100 kPa (11 kg/cm
Minimum:
1,000 kPa (10 kg/cm
Maximum:
1,200 kPa (12 kg/cm
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).
7. Install:
S spark plug
8. Connect:
S spark plug cap
3-16
CHK
ADJ
Diagnosis
Piston wear or damage
 Repair.
Piston ring(-s), valves,
cylinder head gasket or
piston possibly defec-
tive  Repair.
Compression pressure
(at sea level)
2
, 11 bar)
2
, 10 bar)
2
, 12 bar)
13 Nm (1.3 mSkg)