3/4" shaft with 3/8" pitch (#35), 12 teeth, special grease fitting style used on Brister's, Murray, Yellow Jacket, and others.  Replaces Thunder Kart 20420Z0202.  (Engine shaft must be drilled for grease feature to work;  high temperature grease required.)  Grease fittting (20220) not included.

Can be used as a replacement for the 209760A, but it does not have the set screw -- it is held onto the shaft by a bolt and washer on the end.