Mikuni TMX carb issues & 330 big bore kits

I recently picked up a pretty nicely prepared 2001 CR250R that I will be enduro/desert racing locally. The guy I bought the bike from was very knowledgeable, and told me more about the bike than I could really digest at one time.

The bike runs reasonably well. However, the one thing that is proving problematic is the jetting in the stock Mikuni TMX 38mm flatslide carb. He told me that he has the smallest jets in it but that it still runs too rich. After having about 20 rides on it, I can attest that the bike is running waaay too rich. I would like to think that the carb can be tuned correctly but it seems the more I read up on this, the more I hear that the best fix is to install a Keihin PWK Air Striker (38mm). :bang:

Can anyone shed a little light on this. I love the engine on this bike...it has a really nice power delivery down low and through the middle which is where I want it. I would just like to clean up the spooge and the off-idle throttle responsiveness if at possible.

Thanks in advance.

Also, I have heard that LA Sleeve offers a big bore kit for pre-2002 CR250's. I was curious if others are running this kit, and if so: What are the advantages and disadvantages compared to a stocker.

Again, thanks in advance.

I guess I must be only person with the carb problem huh? :coocoo: Well, maybe not...turns out JD Jetting actually makes a kit to specifically fix the problem on the TMX carb. They also suggest that the PWK carb swap is a good solution too.