2002 wr 426 mods

thumperrider · Apr 3, 2002

I just bought a 2002 wr 426 and was wondering what mods to do to it. I have a White Bros. pipe and silencer on the way and have taken out the throttle stop and taken the top of the air box off....WHAT ELSE?

Tree Crippler · Apr 3, 2002

It depends on what your using it for. Racing? Trail riding? Motocross? Tight woods?

thumperrider · Apr 4, 2002

mostly trail and tight woods riding....read something about the grey wire....whats that all about?

Scott in KC · Apr 4, 2002

Ride it with stuff you've got and see what you think. And as mentioned above, decide what kind of riding you'll be doing mostly and go from there. Not sure, but I believe they stuck a big fat needle in yours too. I have the '01 and it came stock with DRR needle and a 75 pilot AIR jet (not to be confused with the pilot fuel jet!) I went to an ELN, 42 pilot, 100 pilot air jet, 165 main, plus YZ timing. The needle alone will really wake up the mid-range hit, the timing change will add MORE hit. And it's cheap, $20 for needle & jets, YZ timing free.

You might also consider a YZ style seat & tank, that is if you plan on turning AT ALL. If I could only keep one mod that I did to the bike it would be the seat/tank...hands down.

Scott in KC · Apr 4, 2002

Grey Wire: remove the seat & tank, the wire runs on the right side of the frame rail, directly under the tank. Simply disconnect or cut the wire and tape off the bare end, or modifiy the plug connection so the circuit is broken. That's it!

It's fun to do this stuff one step at a time to see what difference it makes. The grey wire should dramatically improve the mid-range.

thumperrider · Apr 5, 2002

Hey Scott, thanks for your help. COuld you explain what the grey wire mod actually does? I was wondering if there are any other sites that describe or talk about these mods in a little more detail.

Scott in KC · Apr 6, 2002

The wire apparently changes the spark timing in a way that limits the power that is made through the mid range. This wire is ONLY on the US WR models and not on the Euro, Canadian or Aussie models. I think in conjunction with the throttle stop and that rediculous plug they put in the exhaust, it helps with emmisions. www.thumpertalk.com is another good source for WR specific info...just do a search first, especially on topics like this that have been rehashed a 1000 times.

Tree Crippler · Apr 7, 2002

My jetting is very close to Scotts. I have a litte bigger main. Lower the forks for turning.

Scott in KC · Apr 7, 2002

TC, did you do that "KL" mod on your 400? Just curious. I'm helping a buddy with his FCR he put on his 400ex quad and I have to get the squirt reduced on that pumper too.

I always had a hell of a time getting my bike to lay over and turn. I mean it just stood right up no matter how hard I cranked it. Man, I dropped the clamps (raised the forks) about 8mm, what a difference.

Tree Crippler · Apr 9, 2002

Are you talking about the BK mod ? Thats the only one I didn"t do. I think Wayneo who has the same jetting changed it.

Scott in KC · Apr 9, 2002

TC, your carb is different than mine & wayneo. You can do the BK mod (shortening the duration of the pump squirt) but you have to go about it a different way. Ours they put this little tab on the body of the carb that is in the perfect spot for stopping the acclerator pump cam, like it was made to have a screw & spring added to do exactly this. Yours you have to modify the actual pump rod to get the squirt reduced. Made a hell of a difference in the feel of my bike...very snappy...no bog at all. The biggest thing to get used to was running my idle higher...it isn't an XR by any means!

2002 wr 426 mods

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