The circa 1970, SE Asian, restored Vespa actually belongs to my friend. He's storing it in my garage for the winter and during that time we'd like to diagnose and repair the problem.
He bought the Vespa early this summer and used it as his primary commuter for the riding season, during which he had no problems aside from a broken clutch cable. On the way to my house to store it, it stalled a few blocks away and would not restart so he pushed it the rest of the way. At my house, it still would not start and, in fact, has tremendous resistance when we try to cycle the engine.
Any guesses? Any known problems that might cause something like this?