I have a 1997 Warrior 350.I noticed lately that at wide open throttle the engine feels like it misfires,but when I back off the throttle just a little bit the misfire goes away.The bike runs fine otherwise,only at wide open it misfires.I have replaced the spark plug and air filter(k&n).The engine is stock other than the K&N filter.Any ideas what could be causing this?Bad jets?Dirty carb?Coil??

 

prolly a dirty carb or maybe a coil going bad, or loose wire somewhere possibly, also check your parking brake sensor