Does the frame have ribs welded on it? Hard to tell from the pic but it almost looks like it might. If so, it was a 450 from the factory. It wouldn't surprise me if it's the sidecovers/decals that were changed rather than the engine.Yeah, I think it was a pretty good score. For 1200 smacks I got the complete bike plus another frame (for a single, but not sure if 250, 450...) and a 250 bottom end and a bin full of misc parts. My plan is to get the bike running in its current form, and work on collecting a top end for the 250. If I can ever cobble together the parts to complete the 250 engine, then I'll swap out the 450 to bring the bike back to original form.
There is......there does not seem to be a 'singles only' (ha...would be a good name for a website dedicated to these bikes) forum anywhere.