My son's TM85 does not seem to want to overrev like it is staving for gas, (starts popping at a certain RPM range.) have tried to go to a larger main jet (210) but it did not help, just blacken the spark plug and run fat. The bike came with a 200 main which also was a little fat. Using a (195) main and plug is a good color of tan. I think this bike has a revlimiter and is there a way to disconnect or remap the ignition? I think the iginition system is a Kokusan. I have even narrowed the plug gap which did not help. Can anyone help me with a answer other than going to a japanese bike?