I messed with a Singer 500 yesterday - it was not turning all the way. I oiled everything - still nothing - usually it will loosen up just a little. Note I said it was not turning all the way. SO I pulled out the motor. The machine turned just as purty as you please... The motor was what was locked up. I dropped a bit of T-F on the shaft and worked it back and forth for about a half hour and she turns beautifully. The inside of the machine was void of any oil or grease. Everything turns now - wow even the stitch selectors! The next step is to take apart and clean the tension and then test sew the machine. I put a new cord and a foot petal on it so it should be good to go soon.