Treat your manual as a valuable accessory. Print a copy, place it in a sheet protector, and keep it next to your sewing desk. With the manual in hand, you will unlock the full potential of your Toyota 2800, from perfect straight stitches to flawless zigzag hems.
Increase upper thread tension (turn the numbered dial to a higher number, e.g., from 4 to 6). The manual will show the default tension setting (usually 4 or 5 for medium-weight cotton).