Hello..i have a 2000 Bayou KLF 300 that has low hours on it...When i start the engine up it starts up fine with the choke but as i take off the choke it start's to run terrible and backfires thru the carb and as it backfires...something makes a loud bang or a clunk from in side the engine.The things that i had checked so far is Valve clearence and i cleaned out all the jets in the carb.Then set the air mixture screw while it was running.Anybody have a idea what it might be as i don't have a clue what could be causing the problem...i don't want to dissasemble the whole enige if i don't have to.. I would appreciate any advice...Thanks.

 

I know this sounds off but sometimes a bad battery will cause that, even if it starts the engine ok.

 

again the voltage regulator could be going bad and if not taken care of it will destroy the ingniter and cause intermitent spark