Ran my motor last month and track was rough and thought that was what caused my motor to get to 500 degrees. Ran it again this past Saturday night at a different track, kart was not in a bind but got to 500 again after about 10 laps of open practice. Didn't have any tape on either time and same thing. This was only the second time its been run since getting it back from a rebuild and had the old carb they took off so switched it out before qualifying and same thing 500 degrees in 3 laps. Changed motors and put the same clutch on then noticed it had a bad drag feel to it when you would turn the axle. Put a different clutch on and no problem in the race. Still had same gear and pretty much same tires so don't think it was a setup problem. I did check the clutch that I took off and realized that When I changed the driver I had the shims to tight but seems like that would only effect it at idle and not while on the track running. Checked the motor back at the shop and no signs of a blown head gasket so its just got me stumped as to what's going on..