Started right up last week in the cold with about 6-7 pulls. Set to run at around 2/3 constant throttle right now....but that can obviously be altered. Kohler K301 Model S SER# B183761 SPEC# 4773B Shaft is tapered and size is approx. 1-7/8" long x1-1/2" wide at engine block and 1-3/8" wide at outermost point and keyed as per pictures. BOLT MEAUSUREMENTS: The top bolts are 4" apart horizontally. The bottom bolts are 5.5" apart horizontally. If you measure from bottom bolt to top bolt, it measures 6.25" almost vertically. Shaft can be converted with a little motivation! Somebody has spent a lot of time painting and making look very pretty not sure what piece of equipment this might have come from, but i know the K301 was on everything in its day, inluding Cub Cadet, Wheel Horse, Gravely, Miller Welder, and Kohler Generator. Would make a great centerpiece on a tractor restoration!!! I have also seen these on cement mixers as well. if you have any questions, call Adam (201) 803-3269 Make your best offer please.