I used this clutch set up on an older Yerf Dog kart with the Robin 7hp engine. It fit just fine and used the 5/16-24x2-1/4" bolt just like the manual stated (not included). I did have to add a flat washer also. Good low end torque and top end is faster than I can safely test off road. Seems to be a duplicate of the old Comet I removed. The Comet rusted bad but this clutch is zinc plated. Belt was included.