Which position is the needle in? Mine runs hot, and I found since I leaned it out a notch on the needle it runs way better. Also, make sure the cam chain is at the correct tension and the valves are correctly adjusted. Was the oil changed recently? My 100 used to be very bad but now after a complete top end rebuild and adjusting everything, it runs great. Oh yeah, don't hold it pinned all the time, as this will contribute to overheating. I usually ride in a gear high and use the low RPMs.