Thumpstar ATV 125CC, Owner'S Manual

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89 ATV 250 - Periodic Maintenance and Adjustments
TO REMOVE THE SPARK PLUG
1. Remove the spark plug cap.
1. Spark Plug Cap
2. Remove the spark as shown, with the spark plug wrench included in the
owner’s tool Kit.
TO CHECK THE SPARK PLUG
1. Check that the porcelain insulator around the center electrode of the
spark plug is a medium-to-light tan (the ideal color when the ATV
is ridden normally)
NOTE:
If the spark plug shows a distinctly different color, the engine could be
operating improperly. Do not attempt to diagnose such problems yourself.
Instead, have a dealer check the ATV.
2. Check the spark plug gap for electrode erosion and excessive carbon or
other deposits, and replace it if necessary.
3. Measure the spark plug gap with a wire thickness gauge and, if necessary,
adjust the gap to specification.