Just the thing for a big go-kart or mini bike! Our centrifugal clutch assembly with 1" shaft and 14 tooth 40/41/420 chain sprocket just may be the perfect missing item for your serious garage project go-kart. The 1" bore allows this clutch to work with gas engines larger than 6.5 Hp. In addition, the 14 tooth drive sprocket is made for use with the common 40/41/420 chain size.