'02 YZ426 jetting problem

At Sea level, I installed a full exhaust system on my bike recently, a FMF Powerbomb and a FMF Q2. As well as a Dynojet kit, when I was playing with the fuel mixture I leaned it out quite a bit, but I still had a really bad bog.

I was told Accelerator pump timing needed to be adjusted, then I was also told to just leave the stock jetting and turn out the fuel screw and ill be fine. I've toyed with this carb quite a bit. Normally I can figure this kind of problem out pretty quick, but this carb has gotten the best of me.

I have hot cams and uni air filter if that helps at all. The people at dynojet arent too helpful in my situation.

First, be sure you have realistic expectations. You can't really have a 426 that runs cleanly and right that will stand an instantaneous full throttle snap from idle no matter what. But if you are rolling the throttle in a realistic manner, and the bike still stumbles, first get the jetting right. Have a look here for ideas:


Once that's done, try this:


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