I got a new vintage machine today. It is an 1936 electrical model singer, I'm not sure on the exact model number. The serial number is JB 536014. The power works, but the motor doesn't turn the wheel very well. I suspect because the previous owner used the wrong oil, and too much of it. Is taking it apart and cleaning it the only thing that will help with that? The belt is in good shape so I don't think that's the problem. I got it for $30 since the owner was moving and didn't want to take it along.
Here's a photo.