They use Rotax motors. The air cooled Rotax engines where made up until the mid '90's. ATK and SWM used them as well. Parts are available through Bert Flood imports in melbourne. Rotax parts are notoriously expensive. But the engines are well built and reliable. I have a 83 KTM 500 4 stroke with a shot Rotax motor and was quoted $3,500 just for parts.
They seem to wreck a few Can ams on US ebay I see quite a few 175 parts. Mostly early '70's.
Some years back a mate of a mate had a 74 Can am 250 at a swap meet. Fully rebuilt motor, clean and tidy with a spare bike for $250. He begged and harassed me for an hour to buy it. I just wasn't in a buying mood and turned it down. Kicked myself ever since.
I did end up getting a 82 500 Sonic. Paid premium for it, but they are hard to come by.
