Instructions to Adjust Thread Tension on a Serger
- 1). Thread your machine with four separate colors of thread. This will help you to determine the origin of the thread so there is no guessing involved.
- 2). Next you need to locate your tension dials. This is usually on the front of the machine, or if you have an electronic serger, it would appear in the LCD display. The dials need to be turned to the right to tighten and to the left for a looser thread tension.
- 3). Run a piece of test fabric through the newly threaded machine to test the tension. Examine the sewing to see which threads need to be adjusted. If you are seeing loose stitches at the top of the fabric, decrease tension to the closest lower number on your tension dial. If the stitches on the underside of the fabric are loose, try increasing the tension on those threads to the next highest number.
- 4). When adjusting tension, take it one wheel at a time and make small adjustments before running your test fabric again.
Source...