I had a 201 that wouldn't move at all - I cleaned and oiled everything, including tearing down the bobbin area - finally pulled the motor off - the motor was frozen up. It totally disintegrated when we took it off the machine. We pulled a motor off a 15, rebuilt it and the machine turned perfectly. Sometimes you just have hours in them until you get them to work right. There can be a bit of dried up oil in the motor making it move kind of crunchy.