Two rules make overlocker threading manageable: follow the manual’s order, and never thread the needles before the loopers.
The order matters mechanically. Most machines want the lower looper, then the upper looper, then the right needle, then the left. Threading a needle before the loopers means the needle thread sits in the way of the looper path, and you end up doing it twice.
Presser foot up, so the tension discs are open. Same principle as a sewing machine, and the same fault if you forget: the thread sits outside the discs and the stitch never forms.
The trick that avoids all of it: tie-on. When changing colour, do not unthread. Cut the old threads near the cones, tie the new thread to each old tail with a small overhand knot, then pull the old thread through from the far end until the knot comes through. For the loopers this works completely. For the needles, pull the knot up to just before the needle eye, then cut it off and thread the eye by hand — a knot will not pass through a needle eye.
If you do have to start from scratch, use the colour-coded diagram on the machine, thread slowly, and check each thread is genuinely seated in its tension slot by pulling gently — it should offer resistance.
Questions people actually ask
My overlocker has jet air threading. Is that worth it?
For the loopers, considerably — it removes the operation that most often defeats people. Needles still have to be threaded by hand.
I have threaded it and it produces nothing.
Check the order was right and that each thread is under its tension disc. Then check the threads are not crossed behind the looper, which produces a nest rather than a stitch.
Last reviewed 2026-08-11