Sorry its so long just trying to give all the info I can. I was having some issues with my65 9.5 , it was not quite reach wot and the rpm would randomly vary at wotlike it wanted to go faster but would jump in and out of the highest rpm.so I put on a new coil, condenser, cleaned up carb, new fuel lines, tank, cleaned out fuel pump and set points. After all this it was still running about the same maybe a little better. So I did a decarb and it was built up so bad I decided to pull the head and took a razor knife and gently scraped all the carbon off that I could get to,while in there I noticed one piston was a little pitted and the other has a couple of spots where the spark plug was hit by the piston, resulting in having to use j6c plugs which are a lilttle shorter also there is a place on the head cover itself where the piston has hit it. The motor runs good just acts weird at wot an after I scraped the carbon off I took it to the lake and it seemed about the same until the sound of the motor changed during wot, it randomly would get louder not not even more rpm just a different noise. My q's are why can't I reach wot, is it the pistons, why would one be hitting, is it worth taring apart and replacing pistons? Also I noticed the new coil scrubs the flywheel now.Thanks for any help!!!
