Art Reblitz's suggestion that the transmission frame might be warped
is not apparently true.   All shafts spin freely when chains are off.
I thought I was on to something when I tried to spin the right-side
roll spindle with the transmission in 'Forward' -- a fair amount of
drag because of the brake.  However, when I put a roll in and loaded,
unloaded, and even overloaded the brake, there was no appreciable speed
change!

That motor is quite torque-y, having to do chiefly with motor speed
and gear ratios, no doubt.  I'm leaning toward vacuum source issues:
governor, kinked tubing, etc.

Douglas Heckrotte
Philadelphia, Pennsylvania