00WR400 Stock Header

Hello all, I am getting back into riding after several years off. This past summer I bought a 00 WR400. The bike originated in Canada. The exhaust pipe did not have the California Forestry approved stamp on it. So I purchased a White Brothers silencer. I also removed the air filter lid. Other than that the bike is stock. I thought I would only be doing trail riding but got the itch to race. I did my first race ever in Nov 2000 at Prarie City Lilliputian Hare Scrambles. Came in almost last but had a blast. Now I'm hooked. What I would like to know is would it be recommended that I replace the stock header with a White Brothers to match the silencer? My bike seems to be running great! If I replace the header, do I need to do any re-jetting? Any help you can provide will be greatly appreciated. Thanks in advance, Paul.



It doesn't matter what anyone tells you you will not get any performance gains out of any aftermarket silencer or header. For the most part they just move the power around to different spots on the power curve. Several magazines did reviews on all of the exaust systems. I think that they were Dirt Rider and MXA. If there are no dents or dings in the stock header I wouldn't replace it. That is unless you want to feel good about your bike and get easier access to the oil filter. I currently have a FMF power bomb on my WR and a White Brothers header on my YZ. Both look good and give me easy access to the oil filter and both were cheaper than buy a stock header after they were mashed by trees. As far a rejetting that depends on where you live and the elevation that you are at. Here in Michigan I went up to a 185 main ( I think) on both bikes and every thing looks good. You can e-mail White Brothers and they will give reccomended settings for the product. From there dial it in until it ripps. Good luck and have fun.

Thanks Buck.

Yes I would recommend rejetting. The bike stock came too lean.

My settings 00WR

DVP #4

180 main

48 pilot 100 air

YZ timing

I just ordered the EKN needle and will try that out. Looking for more midrange snap. The DVP needle provides very linear throttle response. Great for trails.

The most helpful thing about this site is the ability to search through the archives. Give it a try, if you have about an hour you will learn more about your bike than you may want to know.

Thanks John. I have been going through the archives. Am learning a lot. This is a great site.

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