TNT 1/Jr. hot SAMA

I've got an early SAMA for a TNT / Jr. that gets hot to touch (too hot to handle) after it has been running for over an hour. Something has to be wrong. It doesn't pop or make any motor noise, no problem starting. Just runs hot.

Any advice to address this problem would be appreciated.
Try a drop of Mobil 1 Oil by the entrance of the Motor Shaft to Motor Case itself. Might help. Otherwise, find if you can swap the Motor with a new one?