I would check the belt tension on the motor pulley and the hand wheel. If it's too tight then it could slow the machine down and wear the motor. I noticed a difference when i was adjusting it for my Kenmore's. Once i had it too tight and the motor was having issues. Once i loosened it it worked better. So if you could adjust the tension of the belt, let it loose enough to where you can pinch down about a pinky finger's width then set it, that could help.