Setup/Mods for the '04 WR450.

I'm new to the '04 WR450 and all the mods. I've been sifting through so much jetting crap all over this site it's making me dizzy.

With the basic (throttle stop, baffle removed, grey wire cut, airbox opened) where/how would I find out the right jetting and other setup/mod info that I need for the bike at 500ft alt. What about the YZ timing or any other mods?

If someone has the time and could list the whole lot in one thread, it would make us newbie 'modder's' very happy. If a search is suggested could you list "Words to search for" to save time. Thanks to all you guys who help us out here all the time. Hopefully I'll be helping others out as soon as I've got this all figured out.

I got extra a 160 and 170 main jet and a 40 pilot jet with the bike. Would trying one of these with the basic mods be a better setup than the 165 and 45 that's in there now? :)

There are two main areas to focus on. Get the bike jetted properly for your area. If you go to the jetting forum and do a search on wr450 i think you will find that you will want to go to the 170 main. You may also want to consider going with a jd kit since it includes the 170 main and also has custom neddles that work very well for our bikes.

Step two is getting the suspension to work properly. I ride in the northern woods and needed to have the suspension revalved to have it work properly in the conditions i usually find myself. I would suggest giving the suspension to a local suspension tuner since they usually have a better handle on the type of conditions the bike is likely to be used in and be honest with them about your riding ability. There is big difference between Randy Hawkins' and my suspension settings because there is a big difference in the approach speeds to obstacles between Hawkins and myself. I will leave it to you as to which is higher :)

All the other mods are just personal preferences in my view but the once the bike is breathing properly the two items i mentioned are essential to get the bike up to its full potential.

willy fitz

Willy offers excellent advice!

One thing I wanted to point out though.. you can't "YZ time"

the new WR. It has an auto-compression release. To get the

YZ boost, you need to drop in a YZ cam.


Thanks guys. I ride hard so I want to get the max out of the bike and hence the Q's on the mods.

I will be getting the jetting kit and the suspension look at. :)

So far I've done the usual stuff (grey wire, throttle stop, snorkle removal,removed the exhaust baffle,etc) and installed a YZ exhaust cam. I also installed the following jetting at the same time:

168 main

45 pilot

100 pilot air jet

CVQ needle in slot 4

Zipty pilot screw - 2 turns (get one the stock screw is just about impossible to get to because of the starter motor)

Took it out to the desert for a week over Tday and it ran very well. Also had no starting issues with this jetting. Elevation was basically sea level and the temp was 70-75F.

Having said that I came home and installed a YZ450 exhaust (just the muffler). Did a quick fire up in the trailer and it was popping like mad and shooting flames out the exhaust on accel and decel. I'm thinking the pilot and needle might be too lean. I think I'll richen the pilot and raise the needle a clip. I'm also going to check for any exhaust leaks too but I'm pretty sure it's tight. Anyway that's my project for today. To be honest I'm amazed that there's that much difference in the two exhausts. Is the wr exhaust that restrictive even without the baffle? Anybody got any other ideas?

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