I finally got back to this project. Using the Plettenberg, I swapped in my Quark 80b and the same cogging and extreme heating up occurs. I'm now convinced that there's something like a short in the motor. I have no continuity to the case on any wire but the heat build up is so fast that it could really only be a short.
BTW, with my feigao 8xl in the same set up with the MM, there is a little bit of cogging on start. Not much, but enough so you can't just grab WOT. With the Quark 80b, the cogging completely stops. Much smoother.
Is there anyone in N America who can fix this motor?