Should turn freely with little drag. Check the bearings. When was the last time the rear bearing was oiled if not a powerhouse? If it is a powerhouse generator, both the front and rear bearings are sealed bearings. If it is a powerhouse, I have the part numbers for the bearings. Front bearing *** 6204.2RSR.C3 Rear *** 6203.2RSR.C3 I believe the front bearing on the later generator is same as rear bearing on the Powerhouse.
Make sure to turn in normal direction of rotation. The brushes will thank you for it. Some generators run too close to the pole shoes for one reason or another. Make sure there is an air gap there. The generator should turn freely.
take apart ?