3. INSPECTION/ADJUSTMENT ATV 150/125
Timing Hole Cap
IGNITION TIMING
The CDI unit is not adjustable. If the
ignition timing is incorrect, check the
ignition system.
Remove the timing hole cap.
Timing Light
Check the ignition timing with a timing
light.
When the engine is running at idle speed,
the ignition timing is correct if the "F" mark
on the flywheel aligns with the index mark
on the crankcase.
Compression Gauge
CYLINDER COMPRESSION
Warm up the engine before compression
test.
Remove the spark plug.
Insert a compression gauge.
Open the throttle valve fully and push the
starter button to test the compression.
Compression:
1600 kPa (16kg/cm2, 227.2 psi)
If the compression is low, check for the
following:
- Leaky valves
- Valve clearance too small
- Leaking cylinder head gasket
- Worn piston rings
- Worn piston/cylinder
If the compression is high, it indicates that
carbon deposits have accumulated on the
combustion chamber and the piston head.
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