OK, after your clues and really studying the above picture I think I have it figured out. The belt for activating the bobbin winder does NOT go on the hand wheel and the bobbin pulley wheel as I was doing before. There is no clutch on the handwheel that releases the machine, so when you wind the bobbin that way the machine "sews" away and the motor was getting too hot, too much drag. The belt actually goes on just the motor pulley wheel and the bobbin pulley wheel, under and bypassing the hand wheel. After you get the belt on, you push the whole bobbin winder mechanism up, which pushes the bar back, which pushes the motor back and off the hand wheel. Then the motor turns just the bobbin winder and not the whole machine. Phew!
As I said before, this is a treadle that was retrofitted. My question now is, did the factory do this or did a private party figure out this complicated, jury-rigged system. Does anyone else out there have a set up like this?
Thanks to everyone who gave me clues to figure this out.
Linda