I had a problem with mine being slow years ago and this bolt was to tight ,just have it snugged down now. may not help your problem but worth checking to see if it will help. I think it was binding the gears on mine and causing really slow movement.
Tightened up in A bench vise till flattened out and then swing the pipe around. The second bend on the one end I tightened it up in vise and bent it over with a pall peen hammer .