So i just recently purchased a rmz 450 it has a white bros exhaust and k&n filter on it. When i got it it has some back fire but i didn't think it was that bad because he had said its been sitting for a while and needed a carb clean. i Just figure the pilot jet was somewhat clogged. Took it home and have been working on it, i completely cleaned out the carb and it was still back firing. I noticed the pilot jet was at 42 and the main at 170 so i bumped up to the pilot to a 50. i was thinking this is way to much but i figure since it had an exhaust and filter it would need it. Well the back fire is basically almost gone but still comes in barely at high idle. But now this bike is running SUPER hot like so hot it started melting my radiator guard down by the header and it really started to get me worried. Could it be something else? Ive heard sometime a lean mixture with make the header hot. Do you guys think maybe i need to go up another pilot jet? It is idling a lot better not with the new pilot jet but still has a little bit of a pulsing idle it will go up and down frequently. Not quite sure what could be doing this either. Ones i put it in first it runs great I'm just having the problem with idle and the extreme heat off the header. Any help would be great thanks.