Measuring The Compression Pressure - Yamaha YJ50RAP Service Manual

MEASURING THE COMPRESSION PRESSURE

CHECKING THE SPARK PLUG/
4. Check:
• electrodes 1
• insulator 2
5. Clean:
• spark plug
6. Measure:
• spark plug gap a
7. Install:
• spark plug
NOTE:
@
Before installing the spark plug, clean the
spark plug and gasket surface.
8. Connect:
• spark plug cap
EAS00067
MEASURING THE COMPRESSION
PRESSURE
NOTE:
@
Insufficient compression pressure will result in
a loss of performance.
1. Start the engine, warm it up for several min-
2. Remove:
• center cover
• footrest board
3. Disconnect:
• spark plug cap
4. Remove:
• spark plug
3 - 11
Damage/wear → Replace the spark plug.
Abnormal color → Replace the spark plug.
Normal color is medium-to-light tan.
(with a spark plug cleaner or wire brush)
(with a wire gauge)
Out of specification → Regap.
Spark plug gap
0.6 ~ 0.7 mm (0.02 ~ 0.03 in)
20 Nm (2.0 m · kg, 14 ft · lb)
utes, and then turn it off.
Refer to "SIDE COVERS AND FOOTREST
BOARD".
CHK
ADJ