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INSP
ADJ
IGNITION TIMING CHECK/
COMPRESSION PRESSURE MEASUREMENT
5.Install:
● Timing plug
6.Detach:
● Timing light
● Inductive tachometer
COMPRESSION PRESSURE
MEASUREMENT
NOTE:
● Insufficient compression pressure will
result in performance loss.
● Before measuring the compression pres-
sure, the valve clearance should be
adjusted.
Refer to “VALVE CLEARANCE ADJUST-
MENT” section.
1.Place the machine on a level place.
2.Remove:
● Spark plug
3.Measure:
● Compression pressure
**********************************
Measurement steps:
●Install the Compression Gauge 1.
●Crank over the engine with the electric
starter (be sure the battery is fully
charged) with the throttle wide-open until
the compression reading on the gauge
stabilizes.
WARNING
When cranking the engine, ground the
spark plug lead to prevent sparking.
●Check readings with specified levels (see
chart).
Compression gauge:
P/N. YU-33223, 90890-03081
Adapter:
P/N. YU-33223-3, 90890-04082
Compression pressure (at sea level):
Standard: 900 kPa (9.0 kg/cm
2
, 128 psi)
Minimum: 800 kPa (8.0 kg/cm
2
, 114psi)
Maximum: 1,000 kPa (10 kg/cm
2
, 142 psi)
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