Thanks for everyone's replies. So I rode the bike to work and back today. Definitely an improvement. The bike is strongest between 5-8 RPM. Anything under is doggy and after 8 it starts to get doggy. It can just make redline with no power there at all. At around 7800rpm there is a little hiccup in the power delivery.

The bike is running a 300 snorkel with the stock exhaust and headpipe. The muffles end cap has been cut off and the arrestor removed and a new larger end cap installed (3/4"). The air box backfire arrestor has been removed. The carb slide has been drilled and it's running a 40 pilot and 128 main with 2.5 turns out on the mixture screw.

Based on the above info what would be a good DJ kit to buy? I tried to find a DJ2206 kit on there website but didn't see it listed. Just want a more linear power curve.

Forgot to add the bike is a 2008 KLX250.

 

The #2206 kit is for the KLX300 and would be the one for you since you've drilled your slide. They are easy to find and purchase.

 

You can try another shim, but the KLX300 adjustable needle is the best. Parts are:

16009-1912 Kawi Needle-Jet, N1TC
92037-1401 Kawi Clamp, Jet Needle
92143-1667 Kawi Collar

This may help the transition to the needle at the lower rpm. Start at the second notch from the top, maybe may need to go to the third. We're running around 900-1500 feet elevation and the second notch works for us.

Don't know if you need more than the 128 main. You could try it. We went with the Dial-A-Jet to add fuel as needed. The manufacturer says the adder can do up to about 1/3 fueling. They say jet in then drop two sizes. I forget, but I think I'm running the 125 main. No dyno stuff, all I can say is it had little problem pulling a 15/39 sprocket set up on the road and never was lacking off road with the 13/47 in the deep sand when we were in Michigan.

 

Having recently use the N1TC and the DynoJet needle to work through my carb issues, I can pretty safely say they felt almost identical in terms of power curve and response. The measurements seemed to reflect this as well with the N1TC being a touch shorter over all which presumably would lead to the main jet coming in to play a little earlier.

Klxster has some data regarding what kind of manipulations happen to the AFR's at a given rpm for the needle notch + main jet combo's. We're not sure what the N1TC looks like, but butt-dyno wise it can't be far off.

Can't go wrong with either one, so order whichever gets there the quickest

 

Thanks guys. Found the DJ kit, but at $65 not cheap but worth it if it works.

 

Versus the needle, clip, and collar? You already have the other parts, the pilot and main.

I did exactly what you did, trying to shim the stock needle, trying to save a buck, to no avail. I had a hesitation in the mid range and the needle cured it. As I've said, those modifications have been in the forums since 2007 and I never did find anyone having issues with the full KLX300 jetting. If you do the search you'll find what I did. A lot of riders did it before and also after the advent of the Dyno Jet kit. My brother and I did as well.

You just skipped the one part - the needle. It appears to be relatively critical.

 

So I don't need the whole $65 kit. I need a DJ140 jet and the DJ needle? Can you buy them separately? I definitely know I'm lean. I took the diaphragm out tonight and added a couple of shims under the needle and it performed better for the short ride around the house.

 

Hey klx678, just saw your post on the Kawi parts list. I'll order them up tomorrow.

 

Should save you some bucks and likely fix the issue.

I would say you could find richer jets at the dealer or a shop too, should you need one.

 

Would you recommend going to a 130 or 132 jet to replace the 128 I have with the new needle. I read back in the threads somewhere that it response well with the 132. Definitely running lean. It sputtered on the cool morning commute this morning but ran better on the way home when it was 90F.