hmmmmm so many questions. Carbs are so complicated that it's hard to say without being there and hearing your problem. Has the bike sat for a while? Sometimes if they sit a float bowl or two could get stuck and cause some sputtering. If they're not stuck that bad you can usually lightly tap a screw driver on the bowl covers to free them up, or my favorite....go out and gun out a few wheelies and bounce the carbs around a little. If that doesn't work I would take the carbs off and thoroughly clean them out. If you don't have any other major mods the jet kit you have should run pretty good. If that does'nt work you may have another issue, in which case I would say talk to Jim at 4&6 Racing they have a forumn on the board too!!!