Engine; Engine Inspection; Measuring The Compression Pressure - Yamaha MZ360 Service Manual

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ENGINE

ENGINE INSPECTION

MEASURING THE COMPRESSION PRESSURE

TIP
Measure the compression pressure after checking and
adjusting the valve clearance.
1.
Warm up the engine for several minutes.
2.
Remove:
• Spark plug cap
• Spark plug
NOTICE
Before removing the spark plug, use compressed air
to clean the cylinder head cover to prevent dirt from
falling into the engine.
3.
Connect:
• Compression gauge "1"
1
• Compression gauge extension 73mm "2"
Compression gauge:
90890-03081
Engine compression tester:
YU-33223
Compression gauge extension 73mm:
90890-04082, YM-04082
4.
Measure:
• Compression pressure
Crank the engine until the needle stop rising on the
compression gauge.
Out of specification  Refer to the testing steps.
Standard compression pressure:
450–550 kPa
(4.5–5.5 kg/cm², 65.25–79.75 psi)
WARNING
To prevent sparking when cranking the engine,
ground the high tension cord.
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