Measuring The Compression Pressure - Yamaha F40BMHD Wartungshandbuch

CHK
POWER UNIT
ADJ
4. Install:
•
•
•
5. Connect:
•
•
•
MEASURING THE COMPRESSION
PRESSURE
CAUTION:
Before removing a spark plug, use com-
pressed air to blow away dirt accumulated
in the spark plug well to prevent it from fall-
ing into the cylinder that is being tested.
1. Check:
•
2. Warm-up:
•
3. Remove:
•
4. Install:
1
•
5. Measure:
•
3-16
Cylinder head cover
Spark plugs
Flywheel magnet assembly cover
Blowby hose
Fuel hoses
Spark plug leads
Valve clearance
Out of specification → Adjust.
Refer to "ADJUSTING THE VALVE
CLEARANCE" on page 3-14.
Engine
Spark plug(-s)
Compression gauge
(into the spark plug hole)
Compression gauge
YU-33223 / 90890-03160
Compression pressure
Below minimum compression pres-
sure → Inspect valve clearance,
valve face, valve seat, piston rings,
cylinder sleeve,
head gasket and cylinder head.
Compression pressure
Minimum
1,210 kPa (12.1 kgf/cm
E
1
piston, cylinder
2
, 175 psi)