On further thinking about the flywheel effect I have a number of 500 single Enfield flywheels here and I'm sure I could turn one of those down and heat shrink it onto the PT boss. Another thought I'm having is that the PT being a half crank motor only supported on the bottom side, is the fact the belt tension is part of the issue with it slightly attempting to twist the crank which doesn't happen with the F/C
