Update
The flywheel and hand wheel turn freely when the machine needle isn't engaged. The treadle runs smoothly and I don't feel any areas where it binds up. The belt doesn't slip at all. When I tighten the knob on the handwheel to engage the needle, it becomes extremely difficult to treadle, to the point where the belt slips, and it feels like it binds up when the needle is at the top of the cycle.