Quality Aftermarket Centrifugal Clutch. Fits all 3 HP - 7 HP engines with a 3/4" crank. Commonly used on one wheel Go Karts with rear tires that are no larger than 15" tall. For Go Karts with larger tires and/or Live Axles, we highly suggest using a Torque Converter. 3/4" Center Bore with 3/16" Keyway Bi-Directional (Can Be Mounted Both Ways) Engages at 2200 RPMs Pre Oiled Bushing It is recommended to use an impact when installing the bolt and washer to the end of the crankshaft to secure clutch safely.