I have some good news and some bad news. I finally got around to working on the Alpine. I had the motor timed, and it runs great, but it won't turn the tracks. I checked and it looks like it has the wrong tracks on, as they are way too tight, even in the loosest spot. I am pretty sure they are off a 70, and between 70 and 71, the tracks changed and got longer plus they had more clips. So I don't really know what I am going to with it now. Update: Because its the old style cotton tracks, they probably just shrunk. The sled was actually traded and is now in the hands of a skidoo collector. Would have been a fun ride.
The night we brought the alpine home, we put the 640 in my motoski for the duration of the restoration.
Excellent seat, excellent motor, just needs a paint job and some hood work.
Good ole 640 Rotax, what a powerful motor!! It is working very well in my motoski.