I toured the Yamaha assembly plant and I saw them putting YZ450's together. The first step was to get a FCR carb and then slip the airbox boot on it. They then built an entire motorcycle around it. If you missed the special on A&E last night, David Blaine and Chris Angel both attempted to get the airbox boot on the carb of a YZ450........they both failed. Not really... Before any of you post how to do it, I do know how, but it is nearly impossible without taking the top shock bolt loose. This is the only thing I hate about this bike after having owned 2 previous ones with steel frames. The carb is a bugger to get to. BTW....I did slip in the new needle and gave my carb a cleaning. It seems pretty crisp, but it was before also. I haven't ridden it yet on the track.