i have the TT39. had similar problems, untill i got the needles set right, then of course the temperature here got a lot higher, and i started having problems again. this weekend i tried something drastic, i modified the idle needle, now it is a sweetie again. the mod is to grind a conical section on the end of the needle about 0.060 long and down to 0.030 diameter at the tip. i think what i did is get the carb to have smaller overlap between the idle needle and the high speed needle. but truthfully all i know for sure is it is running better than it ever did. i read a thread recently where a few people tried different variations of that mod. It almost seems like anything you do to the idle needle that makes it smaller works wonders, (hit it with a hammer = bad, grind it down with a file,=good) maybe the 36 carb is the same?


i measure temp around the cylinder not the head. When breaking in i tried to keep it under 200, now i run around 220-240. i don't see why you should have shut down problems under 270 degrees though. maybe try a new plug first?