Yup, several times I have pulled the cap off and the plug top is dirty from what looks like arching. I put a bit of grease on the ceramic and top of the plug this time to make the cap slip on easier.Bought mine at 115 miles - from 115 to 265 miles it fouled a plug every ride. At 265 it shelled a motor. It's in getting a short block and new injectors currently. In regards to fouling the plugs - my dealer stated one of the leading causes of fouling plugs is folks not getting the spark cap snapped on all the way. My sled is very difficult to get it snapped on that final notch. Has anyone experienced the same thing?