SINGER 14T967DC-WORKBOOK QUANTUMLOCK - Manual (Page 173)

5. Before threading the eye of the needle, make sure the thread is behind
the thread guide located on the bottom of the needle clamp.
6. Thread the eye of the Right Overedge Needle .
Thread Middle Cover stitch needle with regular overlock thread.
1. Raise the Presser Foot to release the tension disks. Thread the Cover
Stitch Middle/Chain Stitch needle as illustrated 1-9.
2. Pass thread from back to the front
through the thread guide .
Five-Thread Safety Stitch Narrow page 14