I need help! please!

So my bike was running alright I have a 2002 ktm 125 sx. I rebuilt my top end with another pro lite. Then I replaced my old fmf fatty pipe with a new pro circuit plat. It now has 180 psi compression. Unbelievable right? The bike runs great in bottom and midrange. When you get on the pipe in high rpms it wants to miss and spit amd sputter. It has had a 185 main for the last 3 years. At leasf thats how long ive had the bike. The bikes always run great. Do you think it could be the powervalve? Going from fmf to pc shouldnt make that big of a jetting difference should it? Could it be electrical? Bike starts and idles great. Bottom and midrange is great like it always has been. So that leaves me to believe to lean on main jet? Whats your thoughts?


Put the old dented fmf on and it runs considerably better.

Gonna try going to a 190 main.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now