This the rear sprocket and coupling hub off a 1974 Kawasaki H1 (H1E) Mach III 500 cc two-stroke three-cylinder motorcycle. These are fairy hard to come by. I believe Kawasaki only produced this bike between 1969 and 1975. According to the neck tag, the bike this came off of was built in July, 1973. Everything is in great shape. No noticeable wear on the sprocket, bearing appears to be in good working order, and the rubber is still supple.

This bike was the 500 cc version of Kawasaki's notorious three-cylinder two stroke street bike era-- a piece of motorcycle history! This two-stroke monster-- called the "widow maker"-- was clocked hurtling down the track in its day at about 120 miles per hour, with rear DRUM BRAKES!!! There were front discs, at least-- and this is one of those calipers.

Right around the time Kawaski Heavy Industries were shattering records (and making widows) with these beasts, they we also introducing the world the Z1, to be followed by the KZ series. The rest is history. In my opinion, this bike represents a golden era in motorcycle history-- particularly that of Japanese bikes.

These parts are in great shape. Ready for your project.

Please see pictures. If you have any questions, please feel free to contact me. I am happy to help.