I have a 99 artic cat 500 4x4. When it is warmed up to temp,and under a load,pulling or climbing,or just when you tromp on the gas,it misses and sputters. Otherwise it idles and runs fine. It doesnt do it as bad if you choke it while giveing it gas. We've checked carb and cleaned carb,seems good.We've checked valve adjustment,that was good. New spark plug,new gas,good air filter. Any ideas on the problem?

 

I had the same problem on my cat after some mods to the air box and I went up 2 sizes on the main jet and see runs great now ?

 

What mods did you do to the air box? Right now mine doesnt have an air box because it broke. We just stuck a new filter on the end of the tube going to the carb.

 

I removed the inner part of the lid of the air box