I have a kawasaki AR-80 water cooled. does kawasaki have a bigger engine that will fit the frame of my AR-80?
I don’t know the answer to that exactly, but I had an AR80 about 10 years ago when I was in Bermuda. Cool little bike, and the fastest unmodified bike on the island. A little scary around corners though-rather high center of gravity. Mine was air-cooled though. You might be able to stuff a 125-250 dirt bike engine in it with minor mods, or perhaps a small flathead twin which might help with the handling. Probably have to modify the mounts in any case. Good luck.