Prime Line 7-06002 Centrifugal Clutch for Mini-Bikes, Go-Karts, Riding Mowers, Snow Throwers and Garden Tractors Automatic Centrifugal Clutch Sintered Metal For Smoother Action Limited Slip Engages at 1800-2200 RPM 12 Tooth Single Sprocket with 3/4" Shaft For Use with No. 35 Chain