Idlee Speed Adjustment; Throttle Stop Screw - Yamakoyo YK250 Owner's Manual

4. Measure the spark plug electrode gap with a suitable gauge.
The gap should be 0.028 -0.031 in (0.70 - 0.80 mm). Correct the gap, if necessary,
by carefully bending the side electrode.
5. Install the spark plug carefully, by hand, to avoid cross-threading.
6. After the spark plug seats, tighten with a spark plug wrench to compress the water.
If reinstalling the used spark plug , tighten 1/8 -1/4 turn after the spark plug seats.
If installing a new spark plug, tighten 1/2 turn after the spark plug seats.
NOTICE
A loose spark plug can overheat and damage the engine.
Over tightening the spark plug can damage the threads in the cylinder head.
7. Attach the spark plug cap.
IDLE SPEED ADJUSTMENT
1. Start the engine outdoors, and allow it to warm up to operating temperature.
2. Move the throttle lever to its slowest position.
3. Turn the throttle stop screw to obtain the standard idle speed.
Standard idle speed: 1,400 150 rpm
MAINTENANCE

THROTTLE STOP SCREW

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