While you wait for answers, we may have found some information which could help you.
Click here for Singer Sewing Machine Thread
Singer 507?
Singer 201 went bang , smelt and now won’t work?
the thread is bunching on underside of fabric it looks like birdnest?
Presser foot is loose?
Singer 188K1 presser bar stuck?
Singer zigzag 457 Stylist not threading bobbin/making stitch?