kdx running rich with lean jetting problem solved! and cheap

[dillydalley]

Ok, resurrecting an old subject as a hail Mary. I have an 01 200 with identical problem on the stock carb as the OP except replacing the jet block oring didn't help. Starts and idles well and will clear out up top, but the mid is flogging rich. Jets are 45, 155, stock needle 2nd clip at 2000' and 35-40°.

Now, I've done my research and it's not reeds or crank seal and here's why. I bought the bike not knowing it had a Chinese copy carb and it runs clean. Previous owner bought the copy because he couldn't jet the stock and I now see why. I should probably just leave the Chinese carb in and ride it, but it bugs knowing it's in there and would really like to get back to stock oem. I'm not a big aftermarket parts guy and like everything stock, which this bike is, except for this stinking sudco airstryker copy carb and it's driving me nuts. Anyway I digress.

What are the chances that the emulsion tube in the stock carb is oblong around the needle and how do I check that? That's the only thing I can think of. What else am I missing here? I guess I could drop the needle all the way down, but I'm pretty sure it won't be enough. There's an issue somewhere and I can't find it through conventional means. Any and all help would be greatly appreciated.

[KDXGarage]

I strongly suggest you get a real carb, not a counterfeit one. I think you may have figured out that having a counterfeit carb leads to frustration and lets you decide to have counterfeit performance or realize you need a non-fake one.

Please start a new thread instead of digging up an old one.

[dillydalley]

Oh i definitely hear what your saying. I'm trying to NOT use the Chinese carb. But between it and the OEM carb, it actually is the the one that runs right on the bike. The OEM carb that I'm trying to put back in the bike because I'm bothered with the chinese carb being in there is the one giving me trouble. Also, I forgot to mention that I'm using the same needle between the 2 carbs so I know the needle is not worn out. If I can't sort the problem with the stock carb, I'll prbably just buy a genuine 35mm Airstryker from jetsrus, although a lectron is tempting me as well. But $550ish for carb and throttle assembly is pretty steep.

You think that's where I'm at though huh, replacing the carb? Anything else I'm missing?

Thanks for the reply kdxgarage.

[KDXGarage]

Oh, I thought you had the counterfeit one in there. There have a been a few people come on with them and have issues.

The old one may have a worn bore or needle jet (jet needle, whichever one is the tube). Ourbikes are old, so parts DO wear out. Letting a little air or too much fuel sneak by will wreck tuning.