best 426 after market parts

I put a FMF powercore 4 silencer and rejetted it and that’s the only hop up I've done to it and that gave it so much more torque, midrange, and top end power. But now that I’ve gotten use to it I would like more response and torque, I’m thinking of camming it has anybody put cams in theirs and if so what do you think. :)

You can install an 03 YZ450 ex cam but you have to make sure to YZ time it. Not only does it give you more zip but you can remove you decompress lever because it will then have anto-decompress :) you can also do the other free mods (air box lid, disconnect the grey wire etc)

On the 426, YZ timing is a free mod, you just change the exhaust cam timing. I loved the change on my '02 426. I did not notice any loss of low end, but, I did notice a big hit on the top end. For me the decomp lever is no big deal. I am not motivated to spend money on a new cam just for that, but, if you stall during a race, I can see how the extra few seconds can help.

What jets did you change and what did you change them to?

I changed my pilot to a 45, my main to 175 and my needle to the 4th position


Definatly do the auto decomp 450 cam and YZ time upgrade going.

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