My 07 kx250f has A k&n air filter and a two brothers exhaust, the only aftermarket stuff. And it back fires and pops a lot when I decelerate. Also when I´m riding it heats up alot and seems to run alot hotter then it should. I have a larger piolet jet but I don´t know how big I should go? Or if thats even the problem. Any ideas on fixing these problems? Thanks for anything.