Yz 426 pipe ?

I just bought a 2001 yz426,it has a FMF Q pipe on it Saturday during the rain I decided to put on the stock pipe just for fun.Took it out for a little ride bike seems to rev much qiucker with the stock pipe on.Bike runs great with FMF pipe put does rev up a little slower no bog or anything just not as snappy when you grab a hand full of throttle.Anyone have any suggestions on how to make FMF pipe perform as good as stock.Thanks yes I 'm a newbie so be gentle. :thumbsup:

Not an expert by any means, but I have experienced the same thing on my 400f. However I did notice a much broader power band with the FMF, where the stock appears to make it's power up high.

have you been adjusting the fuel/air mixture between the two? It may make a bit of difference. Just a quick adjustment of the fuel screw really helped mine out.

That's what I was thinking of trying,when I put the FMF back on I will adjust the fuel screw a little.

:thumbsup: let me know how it goes for you

The FMF is letting the bike breathe a little better so you need to adj the fuel mixture. Play around with it...always remember the number of turns you use either way...rich or lean...4 strokes are a bit tricky...try it one way...ride around...adj...if no good...go the other direction...you should find the sweet spot in no time. :thumbsup:

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