While I was out riding yesterday my quad starting giving me a slight backfire/cough after running it at mid throttle and then letting off and hitting it again. It has done it since it was new every once in a while but yesterday it was really bad, other than that it has run great. I checked the plug and the mixture seems to be about right, so I'm not really sure what the heck it is. Has anybody ever had that and how did you fix it?

 

Youre too lean on the pilot circuit. Most likely a 1/4 to 1/2 turn out, on the mixture screw will clear it up. If its doesnt...check for air leaks in the intake area.

 

I'll try that and see if it helps out any. I was wondering if maybe lowering the clip on the needle would help it also? Anyhow, thanks for the input.

 

if it all of a sudden just started happening... then its not jetting.
look more towards an air leak somewhere.

 

I finally had a chance to change the mixture the half turn out and the cough is gone. Thanks for the help.