crocee,
Jim is most likely correct. I was sewing with my Edison clone last night and the machine ran fine at first then started struggling. The motor would growl as it tried to start then would start smoking until I nudged the hand wheel. Then it would run.
I put a different motor on it while I sewed and later pulled one of the brush caps off the ailing motor. When I got the brush out it was covered in oil. So I'll do exactly what Jim said and see if that will cure the problem. If not then the motor will have to come apart.
Joe