We may have found other answers which could help you.
Click here for Sewing Machine Needle Threadhow to get the tension right on my machine?
1965 Singer 275k sewing machine foot pedal?
Bobbin won't wind?
Singer 201 went bang , smelt and now won’t work?
My CG 500/550 Singer Sewing Machine's bobbin isn't working?
Singer zigzag 457 Stylist not threading bobbin/making stitch?