I have a Singer 221 I picked up for $50 at an estate sale, knowing full well it'd be a project machine. At this point I have oiled and greased all the appropriate spots, and it spins fairly smoothly. Not perfectly, but I think I need to run it continuously to flush/work out all the debris it picked up while sitting in a dog crate filled with... well, poop. Humphrey has been through the ringer.
My problem right now is the motor. It spins freely, but makes a loud noise when it does. I took it apart and polished the actuator, cleaned out as much loose debris as possible, and cleaned out the old grease and replaced it with new grease. However, it makes a loud zzzwhir noise when it spins, and spins very very slowly.
My other Featherweight had its motor completely rebuilt by a guy I found (who sadly is no longer in business), and is almost silent and sews like a dream. I recorded a video comparing the two and showing my debugging.
https://youtu.be/RXdIXvQjHCA
Has anyone encountered a machine this noisy, and fixed it? I haven't replaced the carbon brushes or done much to them, I'm wondering if maybe that would help?