Go-Kart Mini-Bike Clutch , Centrifugal 10T ,3/4 inch bore #40/41/420 chain, 1041 Item Number: 1041 Manufacturer: KDI Manufacturer Part No: 1041 Comes with two set screws and a 3/16" key Note: Centrifugal clutches are designed to be used with tires no larger than 15" tall. With a live axle kart you need to run at least a 60T sprocket and then it is only good on flat surfaces. For off road and hill climbing you need a Torque converter set up like our ebay listing 331067225876. Quality after market clutch. Chain not included. Set Screws are included Centrifugal Clutch 10 tooth, 3/4" bore, #40/41/420 chain with 3/16" key and 2 set screws. Common clutch for 3.5-7hp engines using #40/41/420 chain. Mounts onto crankshaft using bolt and washer on the end of the crankshaft or use Set screws to lock clutch onto crankshaft.