A white colored plug is caused by engine overheating. Failure to
repair this engine will result in severe engine damage. Common
causes for this are:
* Incorrect spark plug (too hot heat range).
* Low octane fuel.
* Timing is not set properly.
* Cooling problems, (dirty cylinder fins, no or low water if
water cooled, low or no engine oil).
* Carburetor air/fuel mixture is too lean (too much air).
* Leaking crankshaft seals, no oil, base or head gasket leaks, or
crankcase leaks on two stroke engines.