Necchi Sewing Machine

What you need to do is slacken off the stop motion wheel in the middle of the balance wheel,undo the small screw and take the stop motion wheel all the way off, you will see a three pronged washer, take it off and put it in a different position,pu the stop motion wheel back on and tighten to hand tight only and tighten the small screw up, undo it and see if the balance wheel moves on its own to wind a bobbin, if not then take it off and put the washer in a different position, whilst you have the stop motion wheel off pull the balance wheel sideways slightly and just put a drop of WD40 on the shaft.