We may have found other answers which could help you.
Click here for Thread Tension Sewing MachineToyota SL3404D Overlocker leaving big loops?
How can I mend my Frister & Rossmann sewing machine?
Singer zigzag 457 Stylist not threading bobbin/making stitch?
Presser foot level, needle and thread guide have fallen out?
How do fill a bobber?
The thread loops under the fa?