WR 400 Jetting -carb tuning

4 replies to this topic
  • lemmingscliff

Posted March 05, 2004 - 07:41 AM


I recently finished assembly on my bike in a box and have a few questions. First of all, I ride in Colorado (6000-7000 ft.) The engine I have came from utah. I did the air box mod and the throttle stop as well and put on a fmf powerbomb header and the powercore 4 silencer. Can anyone give me a good starting point for the jets and mixture screw. Also, the screw for the accelerator pump was missing so we put a new screw in it, how far through the other side should it protrude? Any help would be greatly appreciated, Thanks :)

  • Hick

Posted March 05, 2004 - 07:48 AM


Pump adjustment: Screw in until all slack is taken up, then go back out 1/2 to 1 full turn. Adjust to best throttle response. You may also consider something called a "BK mod" (do a search of those terms), the '00 accelerator pump is overly generous...

For your elevation I would try at least 1 clip position leaner. Stock jetting for that model is I believe 165 main and 42 pilot. I would try a 40 and 160.

Hopefully somebody w/ a WR400 at that elevation, or near it, will come along with more specific suggestions.

Hope this helps.

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  • MN_Kevin

Posted March 05, 2004 - 08:12 AM


what year WR?

  • Hick

Posted March 05, 2004 - 08:51 AM


what year WR?

Wow, I thought the post indicated it was an '00 WR.

I was hallucinating. :)

  • lemmingscliff

Posted March 05, 2004 - 03:13 PM


It is a 2000 WR, you werent hallucinating, youre psychic.
Thanks for the help.


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