Measuring The Compression Pressure - Yamaha 5YF2-AE1 Service Manual

MEASURING THE COMPRESSION PRESSURE

EBS00061
MEASURING THE COMPRESSION
PRESSURE
NOTE:
_
Insufficient compression pressure will result in
a loss of performance.
1. Measure:
• valve clearance
Out of specification → Adjust.
Refer to
CLEARANCE".
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Disconnect:
• spark plug cap
4. Remove:
• spark plug
CAUTION:
_
Before removing a spark plug, use com-
pressed air to blow away any dirt accumu-
lated in the spark plug well to prevent it
from falling into the cylinder.
5. Attach:
• adapter
• compression gauge 1
Compression gauge
P/N. YU-33223, 90890-03081
Adapter
P/N. 90890-04082
6. Measure:
• compression pressure
Out of specification → Refer to steps (c)
and (d).
Compression pressure (at sea
level)
Minimum
1,040 kPa
(10.4 kg/cm
Standard
1,200 kPa
(12.0 kg/cm
Maximum
1,340 kPa
(13.4 kg/cm
3 - 15
CHK
ADJ
"ADJUSTING THE
2
, 147.9 psi)
2
, 170.6 psi)
2
, 190.5 psi)
VALVE