Exhaust pop on decel with FMF powercore4 slip on

The bike is a 2007 WR450F and is stock other than the usual free mods and jetted for the stock pipe. Once I put the FMF Power Core 4 on it I get the occasional POP when chopping the throttle. I have an adjustble fuel screw. Should I adjust it in our out to try to eliminate the decel pop? If so how much. It does not happen all of the time just enough to be annoying.


A little popping on decel isn't bad, as long as it isn't excessive. Turn your fuel screw out roughly 1/4 turn at a time to richen the mix and eliminate popping. If you stall off-idle, or the hot-start is required too much (where it wasn't before) to restart, you would need to go back a tad leaner (in).

Thanks. That is exactly what i was thinking. I appreciate the help. :banghead:

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