List of mods for 05 WR450???

This month's Dirt Bike magazine has an article specifically about the "free mods" for the '05 WRs.

Maybe I go run out and find one.... but doesn't such a list exist here somewhere?

I'm about to do the mods and here is the list I've compiled so far:

Main Jet (I just got a new jet #168 but the JD kit seems ideal)

Starter jet (#68 is what my dealer said to use but others have said #72 works well)

Pilot jet (#48)

Leak jet (maybe - I've been told I don't need to do it)

Throttle stop screw (Shorten to 18mm not including the head or switch out to YZF screw)

Zip-Ty fuel screw

Remove air box snorkel (Is additional venting necessary?)

Pull exhaust baffle

Remove gray wire (if you want to change to YZ timing)

I think those are the main ones but I know there are others that can be done. Anyone feel free to add to or correct anything I've listed here.


This gives you info on free mods. Written for the 250 but, are good illustrations for all.

Your '05 will have variances to some of these mods.

In a nutshell here's the way I see it:

1. Throttle stop - when you first get your bike it's half throttle. Can't have that so, we change the throttle stop.

2. Gray wire - now that we have full throttle, our c.d.i. map is still mapped for 1/2 throttle. Can't have that so, we dis-connect gray wire (on the 05 it's in a six pin wire harness under the tank, right side).

3. Exhaust snorkle / Air box - now the bike needs to breath better so we remove the exhaust snorkle (take off the end cap, remove 4 bolts, re-install end cap) and open up the air box (remove seat, take out snorkle behind the battery. some people even cut out the holes on right side of air box, up to you).

4. Jetting/Fuel screw - once you get all this done you find out it's too lean. The 05 needle is non-adjustable and the fuel screw is blocked off and the jets are lean. Change needle to an adjustable type (jd or 04 model) pluck out the fuel screw blocker and change screw to zip - ty or the like. Up the jet sizes (main,pilot,starter, etc) to your elev and temp. Adjust fuel screw approx 1 3/4.

5. A.I.S. removal - lowedog kit - remove ais to rid the backfire on decel (after all these are done)

These are just basic mods to tune your new bike. Theres lots more you can do but this is a good start. Feel free to ask any questions you may have.

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