recently added white brothers carbon pro exhaust. jetted carb with stage 1 dyno kit.
ran fine for a little while now it's starting to sputter and pop any ideas?

 

its probably running a little rich
what was the stock size jet?
and what size did you put in?
also did you put a full system or a silencer?

 

Since it ran fine in the beginning, it might not be a jetting issue which should show up as a problem immediately if the setting was incorrect. Check the air box bottom for any engine oil residue. Also, check for any air intake leak.

 

don't remember the stock size jet. put 120 in the front and 124 in the rear. it was a full exhaust.

 

the sputtering started when we went to kentucky. thought it might be an altitude thing but got worse back in va.

 

what does it mean if there is oil residue in the air box. i ask because i did have oil residue in the air box of my prairie 360.

 

I' ve got a kfx700 and I am just learning about it but on kfx700.net, those guys talk about a 12 hole airbox mod. after they pipe and jet it. In alot of cases , all 12 holes are not open depending on jetting and altitude but I agree with the others that I would check jetting first. I do remember reading that a couple guys were having similar problems and were told to get it breathing on the front end better with the airbox mod. Good luck...let me know how it turns out!![img]i/expressions/face-icon-small-smile.gif[/img]