01 wr426 jetting suggestions

I have read quit a few of the past post on jetting but can't seem to find what I am looking for. I ride anywhere from 2,000 ft. to 6,000 ft. My bike seems to cut out and pop when I am in first and second gear at the higher rpms. Once I shift into third gear and up it runs great. Could this be jetting ? If so what specs would thumpertalkers suggest ?


I think you should try a YZ needle.

But then I always say that.

If it were my bike this is what I would start with:

EKQ needle, clip # 3 (4 over 3,500 ft.) PN: 5JG-14916-E1

42 pilot (stock) (40 is much better over 5,000 ft.)

162 main (stock) (158 works good at 6,000 ft.)

100 pilot air (stock is 75) PN: 7A9-14943-27-00

Set fuel screw for conditions.

Hope this helps.

Ive been really happy with the way my bike runs at about 750-1000 ft here in Michigan. All my info is in my signature.

Try my setting's...Hey! their just like Hick's!! Well close anyway's. I run from sea level to 6000ft and it rip's. When temps drop, it does seem to richen up a bit. (against all logic)

Thanks for the suggestions, I will give them a shot.

After tearing my carb out and looking, this is what I found.






Does this sound OK ? I have only owned the bike since December and I have never fouled any plugs although when I checked the plug it was pretty black. Any suggestions on the brand of plug to use ? The bike seems go run like a raped ape to me other than it cutting out a little. While I was in the carb I lowered the needle to clip#5 I am thinking this will help but I have not had a chance to ride it. Any thoughts or suggestion would be appreciated. :)

By changing the clip to #5 you actually will richen up the mix at low throttle, it will lift the needle. If you are fouling with black deposits it sounds rich already. I'd try the other way, lean it out by raising the clip to #3 which will drop the needle. Id also definately try the 42 pj, it made my bike start easier and foul less.

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