One place to find all WR free mods?

Ok! After a little study, I bought a used 1998 WR400 for a good price.

I have found a number of threads and articles on "free mods." Rather than going through searchs for each, is there one place that identifies what and how for the mods. As far as I can tell the "free mods" are: Grey wire, air cleaner cover, throttle stop, light blue wire, YZ cam timing and exhaust baffle. Did I miss any?

By the way does anyone have any experence with the GYT-R baffle? Seems like a cheap alternative to expensive exhaust.

Lastly, when I make all of these changes do I need to re-jet. I can handle everything else, but have always been a idiot when it comes to carb adjustments (other than stock).

Thanks now for what I'm sure will be a lot of grief, I mean help, from all of you!

There is no doubt that you will have to rejet.

Thanks, I found that one early in my search but it's nice to know I'm looking in the right places.

Here's a GOOD reference WR400 Modifications

Is there a site for the 2002 WR426 ??

I am interested in the dyno numbers for that machine.

Can you post your findings?

I am in the same boat, have a '99 WR400 that is totally stock and in need of some performance gains.


while it is written for the 250F's, the 250F FAQ contains a lot of information which is also immediately applicable to the WR400/426/450.


or use this handy index page to navigate:

for example, there is an excellent page on jetting which will help you understand what's what on the FCR carb:

and, the FREE MODS page covers everything you wanted to know about the airbox, gray wire, etc.:

jim aka the wrooster

'01 wr250f

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