Originally Posted by MingRidesBikes
Hey guys had some questions for ya about the wr426f. I recently purchased an 01 wr426f. looking to get the most power out of this bike. I had a 05 wr450f deristricted that was an absolute blast to ride. With that said I like my new to me 426 a lot. Smooth shifting, linear power band, but would like some more umph. it currently has a yz426 pipe on it. what mods will really bring it alive? I was thinking over the winter to do a yz450 exhaust cam, was contemplating getting a yz426 aftermarket pipe (i.e. fmf or a t-4) not sure how much more power that would be than the current yz pipe on the bike. Anything else to help bring this bike to life? And honestly will it ever have the power the 450 had? Thanks for your input guys.
Make sure this is done first: http://www.thumperfaq.com/throttle.htm
The WRs can only open to 3/4 throttle from the factory. That site is for 250s but still applies to your bike. Check out the other free mods on there and do all of those. Also get your jetting squared away and if you have a bad bog look into messing with your accelerator pump. I've heard people say the 426s can be just as fast with the 450s with the basic mods.