This clutch is normally used in the commercial industry market, but we have found it to work very well on racing lawnmowers. It has a 3.7 inch diameter pulley for an AB cross section belt and will fit a 1 inch crankshaft. This clutch is very tunable with different springs. It can also be purchased with a 3/4 and 7/8 bore.
Clutch is set up for 1500-1800 rpm engagement.
Other springs available for different engagement, see Clutch Spring Set.