HELP!!! 1997 Yamaha Big Bear 350 exhaust problem

[shayboo]

I need some help here-my exhaust is turning red-hot at the head and we have tried cleaning the carburetor,checking plugs and can't figure out what might be causing this. Any assistance would be appreciated.

[cadillacdude1975]

have the carb settings been adjusted in any way? if it is running with the wrong mixture, that could cause the head pipe to glow.

[shayboo]

The only screw I can find on the carb is the idle screw cant find the air mixture screw. Do you know where it is??