Measuring The Compression Pressure - Yamaha YZF-R7 Owner's Service Manual

CHECKING THE SPARK PLUGS/

MEASURING THE COMPRESSION PRESSURE

5. Check:
• electrodes 1
Damage/wear
plug.
• insulator 2
Abnormal color
plug.
Normal color is medium-to-light tan.
6. Clean:
• spark plug
(with a spark plug cleaner or wire
brush)
7. Measure:
• spark plug gap a
(with a wire gauge)
Out of specification
Spark plug gap
0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
8. Install:
• spark plug
NOTE:
Before installing the spark plug, clean
the spark plug and gasket surface.
EB303060
MEASURING THE COMPRESSION
PRESSURE
The following procedure applies to all of
the cylinders.
NOTE:
Insufficient compression pressure will
result in a loss of performance.
1. Measure:
• valve clearance
Out of specification
Refer to "ADJUSTING THE VALVE
CLEARANCE".
2. Start the engine, warm it up for several
minutes, and then stop it.
3 - 20
CHK
ADJ
Replace the spark
Replace the spark
Regap.
13 Nm (1.3 m · kg, 9.4 ft · lb)
Adjust.