James Dean; Help (again)! Jetting grief.


I am still having jetting problems. I have a '00 WR 400; stock exhaust with VOR tip.

Changed to YZ timing; did the grey wire mod at the same time; installed the EKN needle, 4th position. 165 main, 45 pilot, 1.5 turns out. stock pilot air jet.

Went riding at 2,500 feet this weekend (I typically ride 1,000 - 2,000 feet); would barely run at 1/4 to 3/4 throttle (missing terribly). Also has fouled 2 plugs when starting since the mods. Plug is BLACK.

Changed needle position to 5th (leaner - only one more remaining!). Ran much better, but still some hesitation at partial throttle. I can hold at partial throttle and feel it missing.

Should my bike be running this rich?

I have read much about the BK mod; but read it can't be performed on the '00 WR.

My bike ran MUCH better before I rejetted and installed the new needle (170 main, 45 pilot, 1.5 turns out).


Your help would be appreciated.


Atlanta, GA


When you say 5th clip, do you mean 5 from the top? First clip, on top of the needle is the leanest, bottom clip is the richest.

Unless I am mistaken, the BK mod is for the 2000 and 2001 WR's. The 98 and 99 (like mine) will use the KL (Kevin Lysdahl) mod, when I finish my prototype up.

Greg, I run the open exhaust and periodicly run a vortip. when I do I have to change my jetting quite a bit leaner at least one size down on the pilot circuit and 1 clip leaner on the needle. otherwise I foul plugs like crazy!! Hope this helps The EKN needle will work with the vortip if you get it set up right. but I can't just slip it in and out like a lot of guys have said here. I definatly have to lean her down. Also take a look in the ends of the vortip and make sure the welds aren't plugging up the hole. I had to drill out two of the holes on mine to get the blobs of weld out of the holes.

Hope this helps


I just put the ELN in my '01 and found the same thing...that needle is quite rich. Try a 42 pilot and keep dropping the needle. I found that one needle position is HUGE. I was getting a horrible sputter that one clip leaner got rid of.

Side note- when refering to clip positions (at least on this board) everyone refers to clip #1 at the TOP of the needle as listed in the manual. Just trying to avoid confusion.

Good suggestions by everyone.

I need to ask if you took out the slide and throttle plate during the needle replacement. The plate can be installed upside down and messes up the jetting. This would not be the first time.

There are 7 clip positions. Which one are you using? #4 is the middle, #3 (leaner) leaves 2 more positions, and #2(leaner yet) is still a good possibility.


Hello Kevin,

5th from the bottom, of course.

I've owned 43 bikes and am a pretty good bike mechanic.I'm not too proud to ask for some free advice though.

I had read some much good "press" about that EKN needle, I thought I would try it out. So far my experience has not been good. It just seems odd I need to go leaner than the other folks I've read about. Any ideas? I will pull my baffle to make sure it isn't clogged for some reason.

Thanks. :)

Thanks everyone,

I will drop down to a 42 pilot and see what happens.

Right now a I am one position away from full lean on the needle. That does not leave me much adjustment for when I go to Colorado each summer! Hopefully going to the 42 pilot will do the trick. Changing fouled plugs is no fun!

How about that BK mod? is it possible on a '00 WR?

I will report the results.

Thanks again,



No, I did not remove the slide.


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