Measuring The Compression Pressure - Yamaha YJ125S Service Manual

MEASURING THE COMPRESSION PRESSURE

1
EAS00067
MEASURING THE COMPRESSION PRES-
SURE
NOTE:
Insufficient compression pressure will result in
a loss of performance.
1. Measure:
8 valve clearance
Out of specification
Refer to "ADJUSTING THE VALVE
CLEARANCE".
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Remove:
8 cover
8 rear carrier
8 side cover (right,left )
8 hook
8 front cover
Refer to "COVER AND PANEL".
4. Disconnect:
8 spark plug cap
5. Remove:
8 spark plug
cC
Before removing the spark plug, use
compressed air to blow away any dirt
accumulated in the spark plug well to
prevent it from falling into the cylinder.
6. Install:
8 compression gauge 1
Compression gauge
90890-03081
YU-33223
3-17
CHK
ADJ
Adjust