All 2st Jetting Chat - Need Help? Post Your Questions Here

I guess you mean clip slots? There are 5 on red and blue.

Ok this is an update. With the 390 main in I felt there was still something left but was afraid to go leaner because it was feeling like the 91 pump gas was on the edge of detonation. I bought some Sonoco 110 and mixed it 50% with 91 and leaned the main out to a 380. This is a better set up and will be a lot better in the heat of the summer when the air is not as good.

I need to ride a few other bikes to get a comparison but the bike pulls so hard off the bottom and all the way through I can't help but wonder what a 300 is like. Next step, get a tall seat and the suspension done so I can get to the standing position quicker and stay on it.

try a keihin

My 09 WR250 was hard to start until I leaned it out. The plug got progressively more fuel fouled until it was impossible to start. Now mine has been starting 1st kick hot or cold.

corey43,
I think your pilot is too rich. Try a 35 pilot with GAY needle in 4th. I'm at 6000 ft and using 30 Pilot, Air Screw out 1 1/2 turns, and GAY in 3rd and it works really good.

Ok, Thanks Guys! Hopefully it works.

+1 on the 35 pilot. Please repost when you get the 6000 ft jetting sorted as I will be riding in CO at about the same elevation someday and would like to know what you come up with.
I don't know about the other bikes like the 125s but the stock Mikuni with the stock needle is working great on my 09 WR250.

I will hopefully get to do some testing this weekend when I drive east a few hours to get away from the snow.

So where should my air screw be at.

That is what I expected my settings to end up like at your altitude although I doubt the 350 main will work until your above 8000 ft. I might add that I like mine set a hair on the rich side to smooth out the transitions between circuits and keep from going lean on those really cool dry good air days.

Today in MO I went to the 370 main and it pulled harder at high rpm and didn't lose any mid-range pull. On another note I played around a little with the float level and found out that if you get it too low it runs completely erratic. Special attention must be paid to the clip that retracts the needle from the seat, if there is too much play I think the needle might stick a little and cause the fuel level to drop too much before it opens, causing it to go lean and get behind until you lift off the throttle. The spring loaded needle is not my favorite set up to get an accurate setting so I went as far as blowing through the fuel inlet line while raising the float manually to get the exact height that the fuel is shut off.

I purchased a used Keihan PWK A/S for my 167 and the top has no threads in it. Does any one know the size/ pitch for the threads that are on the cable guide so I can get a tap? Sorry if this post is in the wrong place.
Thanks Bill

Would a low float cause the bike to load up on small down hills? I have the jetting dialed in with a tan plug after a plug chop and it runs clean low-top. But after a short down hill it loads up and takes a bit to clean it out. I've also noticed that it drips gas if the bike is anything but straight up.

A high float will cause that.

High is right. I guess I was thinking of holding the carb upside down. I lowered it and rode today with no real change. Guess I just need to ride it harder. But at least the dribbling stopped.

I am still running the Keihin PWK 36mm Air Striker from the 2011 KTM 150XC. I am running the 170 main jet (Stock), 6.0 slide / throttle valve ( stock is 7.0), NOZH needle in the #2 position (Stock NOZI #3), and a 35 pilot jet. I had to adjust the Air Screw out to 2.5 turns.

Hey Johnny,
I know you have been working on your settings a long time. I am one notch richer with my red needle on my 250 and the same pilot 1 1/4 turns. My bike idles high when I stop. I like the way it runs but I'm worried it's a little lean. Does your bike idle right down?

Ok. Yes, my bike goes down on idle as it should. Maybe you are slightly lean on your pilotjet. As it idles high with the airscrew quite a bit close to lowest setting i would try to go up one size on the pilot (42) and maybe around 2 turns out. You don,t have to worry about it running lean on idle. You won,t damage anything. What happens if you turn the airscrew 1/2 turn in just to see what happens?
Johnny

What you say makes sense. What I don't understand is why you and I are so lean. We are way leaner than the JD recommendations. After top notch red, there is no place to go leaner. I ride that bike at 2000-2500". If I had to ride higher, I would probably need to get a different needle.
I had to raise notches on the red needle after I had my squish set along with combution chamber reshape and RB designs carb divider plate. I guess there is just way more signal?

I feel the same way about my 09 WR250