Compression Pressure Measurement - Yamaha F115A Service Manual

INSP
ADJ
GENERAL
3390
1
3391
4. Tighten:
• Spark plug
Spark plug
25 Nm (2.5 m • kgf, 18 ft • lb)
NOTE:
• Before installing the spark plug, clean the
gasket surface and spark plug surface.
Also, it is suggested to apply a thin film of
anti-seize compound to the spark plug
threads to prevent thread seizure.
• If a torque wrench is not available, a good
estimate of the correct tightening torque
is to finger tighten a the spark plug and
then tighten it another 1/4 to 1/2 of a
turn b.
COMPRESSION PRESSURE
MEASUREMENT
CAUTION:
Before removing a spark plug, use com-
pressed air to blow away dirt accumulated
in the spark plug well to prevent it from
falling into the cylinder that is being tested.
1. Check:
• Valve clearance
Out of specification → Adjust.
Refer to "ADJUSTING THE VALVE
CLEARANCE" on page 3-13.
2. Warm-up:
• Engine
3. Remove:
• Spark plug(-s)
4. Install:
• Compression gauge 1
(into the spark plug hole)
NOTE:
Use a compression gauge that is used for
automobiles.
3-23
E
3