Okay, so. Sorry it took me a little while to get back to this. But I did move the motor (and I was even smart enough to mark the location before loosening the screw!) and get the belt off, and in my judgment, it performed about the same as when it's actually sewing. So I took a look at the foot pedal itself, and I can see some rust on the spring, and when I hold it next to my ear and move the pedal it's kind of skreeky-sounding (yes, that is the official term!
). However, there are absolutely no screws to take it apart to clean it--everything is riveted. I obviously don't want to spray WD-40 or anything around an electric component, so I don't know what to do--should I just give up and replace it even thought it does work, or is there some special way of lubricating/cleaning these so they work smoother?
Also, I'm still concerned it could be the motor because of the fact that there's a hum from the motor for several degrees of pressure on the pedal before it starts to move, with and without the belt attached.