look at the back handwheel where it connects to the machine and at the pulley,,see'll where pieces of that meet each other , very slight gaps oil those,, loosen that thumb screw ,, try to keep the needle bar from moving , then by hand work the handwheel.. you want the hand wheel to rotate and not the needle bar ...
I found on mine, the winder pulley goes on top the belt, when you wind push on that with your thumb,, when it wound, put the belt back over the top, push the winder against the machine
run the belt as loose as you as you can without slipping