85 main jetting klx110 did nothing? need help!!

[alcapon1]

I got a 85 main jet for my 07 klx110 and it looks no different then my stock one. I was going to put a 40 pilot but they gave me the wrong size. I can feel no difference, maybe a little better throttle responce in the early revs but I really dont know. Any advice? . I have a Yoshi exhaust and uni high flow filter and I cant seem to get it to stop backfiring when letting off the throttle on the high revs, PLEASE HELP ME

[PlanetMinis.com]

[Calif-klx110]

Did you change the exhaust gasket on the Yosh pipe or use the stock one. My son's 05' did the same when we installed the Dr. D. Turned out the exhaust gasket was old and was leaking causing air to be sucked in.

[Motodad]

If it is backfiring when chopping the throttle, you have an exhaust leak.

[adumb]

If it is backfiring when chopping the throttle, you have an exhaust leak.

or a lean jetting condition

[Trick Daddy]

Most likely an exhaust leak. You should have the bigger main installed and definitely the 40 pilot if the airbox is removed. The 42 will not run right.

[Trick Daddy]

I'd just get rid of the airbox. I ran a stock 110 with the airbox installed and I preferred the stock filter element. I got a little bit of popping on decel, but only up in the very top of the rev range....typically right on throttle chop...with stock jetting. No running issues and no engine damage...