it fits but its a waste of time, imo. my bike is in the low forties right now with a 14mm bing, that is drilled out from 12. if you get your stock free spirit up there, then you might want to start looking around for a bigger carb. spend your money on the pipe, pull your head gasket, or go to a high comp head, and 14mm bing carb and square intake manifold. that will get you in the 35+ ballpark. also make sure your bike is properly tuned and has good compression.