We may have found other answers which could help you.
Click here for Sewing Machine Needle Repair
the thread is bunching on underside of fabric it looks like birdnest?
Singer zigzag 457 Stylist not threading bobbin/making stitch?
Engine revving up ?
Singer 201 went bang , smelt and now won’t work?
Singer 507?
My CG 500/550 Singer Sewing Machine's bobbin isn't working?