Brand new gokart mini bike Centrifugal clutch 10 tooth, 5/8″ bore, #40/41/420 chain with 3/16 key built in. Variable spring assortment allows flexibility in engagement settings. Fits for mini bike , go kart, mini atv and so on Mounts onto crankshaft using bolt and washer on the end of the crankshaft does not have set screws. Please double check your crankshaft size before you purchase. Specification: – 10T 5/8″ BORE CLUTCH – 4′ 40/41/420 CHAIN Fits Mini Bike , Go kart , Lawnmower ,etc Quality after market clutch: Set screws and chain NOT included . Centrifugal Clutch 10 tooth, 5/8″ bore, for #40/41/420 chain . Common clutch for 2-3hp engines using #40/41/420 chain. Mounts onto crankshaft using bolt and washer on the end of the crankshaft. The 5/8″ bore clutch is used mostly on older engines. Package includes: 1 x Go Kart Clutch