TTR 225 lean on acceleration

I've just got a '01 ttr225 and it hesitates when accelerating hard from a lower rpm. It idles great and the top end is fine also. In fact, you could ride it just a little and not even notice a problem. However, when you are trail riding, it hesitates, misses, etc when accelerating from 2000-2500rpm (I'm guessing). Think of the kind of "snap" you need to pull a wheelie -- you close the throttle and then go wide open. In this circumstance, it hesitates -- I'm pretty sure running lean. It'll do that for one second, and then accelerate hard. Of course this isn't so great for trail riding when you are trying to get the front end light while jumping down or climbing at lower rpm.

I've torn apart the carb twice and cleaned everything, although it didn't seem dirty -- maybe a little bit on main jet. New plug too. The diaphragm is in great shape and needle seems to move smoothly.

Any suggestions?

Have you done any modification or is the air intake and exhaust all stock?

No, everything is stock.

As far as the engine running lean, I'm just basing this on my own experience for diagnosing. It could, I guess, be running too rich and causing the same problem. It just hesitates for .5-1 second after application of throttle. It doesn't always take off immediately after the .5 second, sometimes it runs kinda "missing" for several more seconds.

OK. I checked the pilot screw. Didn't have a significant impact on the problem at all. I changing the setting and definitely got changes in idle performance, but couldn't notice that it helped my stumbling on hard acceleration.

Again, the bike runs very well in almost all respects -- idle, full throttle, high rpm. It just stumbles when going from lower rpm -- 1200-2000 and low throttle application to snapping instantly to full throttle -- where it stumbles for a few seconds.

Try one size larger on the pilot jet. I dont know if the bike will preform with wheelie snaping power really, it has a constant velocity carb...

Went to the local shop and got 45 pilot jet and 137.5 main jet. What a difference! I replaced the pilot jet first, this made the most difference. Night and day really. I then went a little further and replaced the main (137.5). This seemed to improve things a little also. I did some more reading last night (after purchasing the jets) and think I maybe over did it a little -- too rich. Because the jets are so cheap, I may go back to a 132.5 main, or even back off on the pilot to 42.5 to see what happens.

Also, the pilot I purchased had the side holes, which I know now, it shouldn't. Anybody tell me how that would affect things?

That all said, the bike is 80-90% better. Like you all know, you don't get the same "snap" with these bikes that you normally get on a two-stroker. But now, at least it doesn't bog. I can let the clutch out at idle and simultaneously gun it and easily lift the front wheel -- it wouldn't do that at all before.

Thanks to all that have provided info in this forum.

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