Jetting 01 yz 426

I recently bought a 01 yz 426 and I have a DSP full exhaust system on it. It backfires after letting off the throttle. I know I need play with fuel mixture needle, but I was wondering what people ran jetting wise at about 550-700 ft. elevation with an aftermarket pipe.

BK mod

JD jetting kit

ZipTyRacing fuel screw

Definitely adjust the fuel screw, you need more fuel in the idle circuit. It will eliminate the popping. A very small amount of popping is desired when decelerating for the best throttle response. I am at sea level, look at my signature and check the jetting out! :)

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