FDJ Go Kart/Mini Bike Clutch 5/8 Bore #35 Chain 11 Tooth High Quality Go Kart Tractor Mini Bike Cyntrifical Clutch 5/8" Bore Accepts 35# Chain (3/8" chain pitch) 11 Tooth Sprocket Racing Centrifugal Clutch Designed for Single Wheel Drive Karts with Tires no larger than 15" Tall Set Screws Not Included Bi-directional operation, Easy to install Picking the right toy is one of the most enduring dilemmas faced by parents and grandparents, by uncles and aunts, and by godfathers and godmothers. Kids love toys, but nowadays theres too much emphasis on gaming consoles and handheld video games. As a gift-giver, your responsibility is to give them something fun that can get them outdoors. But it must not be dangerous for the kids.So the <span class="a-text-bold">Mini bike Go kart Funkart</span> should be the best choice. <span class="a-text-bold">Bore diameter:</span> .625 inches (slightly smaller than a Dime Centrifugal Clutch 11 tooth, 5 8bore, use 35 chain Predator 2.8 HP 97cc engine,some older 3hp engines Engines with 5/8 inch (.625 inch) output shaft with standard keyway