Yamaha XVS650 - Compression Pressure Measurement

COMPRESSION PRESSURE MEASUREMENT II:gr I «fill
Compression pressure
(with oil applied in the cylinder)
Reading Diagnosis
Higherthan
Worn
or damaged pistons
without oil -t Repair.
Same as
Possible defective ring(s),
without oil
valves, cylinder head gasket
or piston -t Repair.
Compression pressure (at
sea level)
Standard:
1,100 kPa (11 kg/cm
2
,
156.4 psi)
Minimum:
1,000 kPa (10 kg/cm
2
,
142.2 psi)
Maximum:
1,200 kPa (12 kg/cm
2
,
170.6 psi)
**********************************
Measurement steps:
• Crank the engine with the throttle wide
open until the reading on the compres-
sion gauge stabilizes.
A WARNING
To prevent sparking, ground all spark plug
leads before cranking the engine.
• Repeat the previous steps for the other
cylinders.
NOTE: _
The difference in compression pressure
between the highest and lowest cylinder
compression readings should
not exceed
100
kPa (1 kg/cm
2
,
1 psi).
**********************************
7.1nstall:
• Spark plugs
~8 Nm (1.8 m . kg, 13 It ·Ib)
• Spark plug caps
3 - 16