 
                We may have found other answers which could help you.
Click here for Sewing Machine Repair Thread 
                the thread is bunching on underside of fabric it looks like birdnest?
 
                Singer 507?
 
                Bobbin won't wind?
 
                Singer zigzag 457 Stylist not threading bobbin/making stitch?
 
                Singer 201 went bang , smelt and now won’t work?
 
                1965 Singer 275k sewing machine foot pedal?