01' WR426F Newbie

Hi Everyone,

I just bought an '01 WR426 off a freind that bought it and let it just sit in his shed unused for the past two years. I got it from him for a pitance and absolutley love the bike. It has a big pipe on it and sounds trick as.

I have been out of the scene for a while and very new to these performance four strokes. Just wondering if you can point me in the direction of things I should keep an eye on, and what maintainance schedule I should try and stick to.

I took the bike out for the first time on the weekend on some pretty narly bush trails. While I had a ball I think the jetting needs to be played with as it seems to idle a bit high.

First impressions of the bike a great but I am thinking that if I can't get the suspension sorted out a bit better, I may trade it in on a 250F.

The 426 has been fiddled with to get it to YZ spec. Not sure what this entails exactly but I know that the timing has been played with.

Thanks in advance,

Ride Hard,

Luke Orreal

A few questions:

What jetting do you currently have

What is the needle setting

What pipe are you running

Is the airbox top removed

What altitude do you ride


The Airbox lid HAS been removed, I have a Pro-circut pipe. I live on the east coast of Australia so I ride pretty close to sea level (if that is what you mean :banghead: )

As for jetting and needle, I'm not sure. I plan on having a look at that after work tonight. Once I know I'll post it here.

Thanks for your reply,


Waiting for your answers about jetting I could throw some general points.

Advice #1. You need to change oil/filtrer frequently for sure. These guys rev high and need good oil.

Advice #2 Are you running clean oil? Not sure? Change it.

Advice #3 Guess what... time for an oil change.

Grease up the steering bearing, rear shock linkage and arm joints down there. I'm a bad guy for not having done mine yet :lol: but they still work fine... but I know I should not wait for problems to occur... :banghead:

Check the valves right now. Remove the tank, open the cap on the top of the head and check the space between the cam lobe and the valve buckets. At the same time, you'll be able to verify if you have a YZ or WR timing. there are many pictures available showing the diff between the WR and the YZ timing if you do a search cause we discussed a lot about it last spring.

If you have sudden trouble with your bike sputtering or not wanting to start, one good thing to do is to drain the carb bowl. Basically, you only need to unscrew the big bolt under the carb, clean and install back. I don't know why but it sometimes occur that water gets in there. You might not have problems even after a river crossing and for whatever reason having it after a quick wash... you never know.

You might want to try a YZ seat/tank combo. Your balls will thank you for that. Great improvement... I run the Ty Davis IMS tank with guts racing seat. Many like the Acerbis tank. The advantage with those tank is that you don't sacrifice autonomy and you carry fuel lower (bike feels lighter).

TT member "Hamish" is in Australia, owns a 426 and knows the mechanic of these bikes quite well so you might want to follow his threads or even ask him questions personnally because he'll know what conditions you ride in better than many other TTers...

Hope this help.

I use to say that decades from now, the 426 is gonna be remembered by many as one of the best off road machine ever built for its time. Enjoy! :banghead:


Thanks for your prompt reply. I gave the bike a filter and oil change the day I bought it. Regular oil changes are a must I know.

I know that the bike definately does run YZ timing. I will crack it open and inspect the valves this coming weekend, while I'm checking the jetting.

I also have a YZ tank and seat. It was the first thing done to the bike, and boy what a difference it makes! I can move around the bike freely and the weight drop was more then noticable.

Thanks again for your help. The TT forums are the best I have seen around yet.

Ride safe,


Looks like you're on the good track.

Keep us posted with what you find as valve clearances and jetting.

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