What jet kit do i need to put in my 09 klx 250s if i am going to put on a FMF Q4 Slip-on?

 

As long as you dont do anything to the air-filter or air box you shouldnt need to re-jet. I put a Two-Bros slip on and thought I would have to re-jet but it only takes a little longer to warm up and it is amazing the difference.

 

I have an 07 KLX250s, with the FMF Q4 FULL system, and the air box lid removed. Went with the FMF jet kit, using their needle and a 132 main jet. Works fine. Though I'm going to try the 128 because I think it's running a bit rich - though, I'm not really sure how to find that out..