Did the install this weekend. I can't tell if it is making any more power, but it does sound different and starts much quicker. While I had the plug out, I connected it to the stock coil and wire and got a thin orange tick tick tick when I ran the starter. After the coil and wire install, I ran the starter over with the same plug and got a thick white/blue pop pop pop. I was impressed by the difference in the quality of the spark. I may have had a bad wire or worn coil as I was having problems with it in heavy rain. The profire coil is considerably larger than the stock unit and it was not a total bolt on but still gets bolted in about the same location. The wire comes with it's own heavy duty ground strap to be bolted to the cylinder head. All in all I am pleased with the results so far and would recommend it to anyone who needs to replace their stock unit.