I just recently picked up this lt250f quadrunner. When i first got it it was hard to start. adjusted valves a bit and now it starts easy. When it is cold it idles just fine. after it warms up the idle races way high and stays high. If i put it in gear it will idle fine. I have noticed after it is warmed up and i get the idle to come down, it will have a little miss like it is backfiring through the carb. The carb is brand new 30mm. I can not adjust the carb after it warms up. nothing seems to work. I took the intake boot off and checked for cracks, resealed and put back on. I also took the pitcock off and tore apart and cleaned real good. I am not sure what the deal is. Also what are the valve clearances supposed to be? Thanks much!

Also when I turn on the light, it is bright at idle and dims when i hit the throttle. Idk if that can be fixed...