Hop up Kit

I just picked up a WR426FN and wanted to know if a Hop Up Kit exist for it, and if so, where I can get it from. I have a friend who has a XR650R, and he was able to get about another 4-7hp out of it by having this Hop-Up Kit installed. That included pipe, jetting, and air box mods.

Not sure what country your in, so to give suggestions would be hard. If the bike is a US bike. Go to the technical section and read "tips & tricks". You have untapped power available.



86TT225, 99WR, WR timing, throttle stop trimmed, air box lid removed, White Bros head pipe, silencer and air filter. Odometer and headlight removed. Moose hand and mud guards. YZ stock tank and IMS seat. Renthal Jimmy Button "highs" and Renthal Soft half waffle grips. AMA, SETRA.


This site is your hop-up kit. You can gain way more than 4-7 hp just by following the excellent advice found here. :)

White Brothers offers a hop up kit for around $1400.


JJ from WA - 99 WR; WR timed, EKN Needle, Scotts stabalizer, Scotts triple clamps, Pro-Tapers, Michelin S-12's, Terry Cable hot start, MSR Raptor clutch lever, Moose skid plate, Works frame guards, Acerbis Pro Rally guards, Renthal MD-soft grips, Factory Effex graphics, YZ IMS seat base, YZ Factory Effex seat foam and gripper seat cover, YZ rear fender

Eric Gorr is also a great source for go-faster goodies and advice. Look for his web site and forum at www.dirtrider.net

Here's an $80 hop up tip, most are free :D

-YZ timing-free

-Cut Throttle stop if US-free

-Remove airbox cover-free

-Used Stock YZ pipe-$50

-carb parts-$30

Search past posting and archives and you'll start picking it up.

The trick is jetting the bike and picking components based on what changes you want to make. The YZ timing is optional as the WR timing on the '01 sounds to be very grunty :)

Usually pipes respond better to a YZ timed setup.

You're gonna love it and you're friend with the XR won't!

Oh, yeah. Here's the best advice...get your tools out and grease all your bearings (yes, all of them). Steering, swingarm, linkage, wheels. They'll all be pretty dry :D Don't say we didn't warn you !

Generally this bike is TOO fast for the majority of riders. Think about handling -stuff like YZ tank, damper, fork adjustments. These made me quicker than adding more power. Good luck!

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