THE LEFT NEEDLE IS YELLOW, THE RIGHT NEEDLE IS BLUE, THE UPPER LOOPER IS RED AND THE LOWER LOOPER IS GREEN
A five thread serger has 3 different loopers.
1. Upper looper - looks like it has its nose in the air. Depending on the brand of serger it may be threaded first - check your manual for threading sequence. The thread from the upper looper lays on the right side of the fabric or top. You can see the stitches formed as you are serging. Often times decorative thread is used in this looper for the "WOW" factor.
2. Lower looper - often feared for no reason. It looks like it is left-handed with the elbow bent. At times decorative thread is used in this looper for home dec projects. You can see the stitch formed on the underside - looks like a "Y". Also, this looper is the one that is used for achieving the perfect rolled hem. It can be tightened to pull the other threads into position.
3. Chain looper - It looks like the lower looper but appears like a right handed elbow bent. This looper is used for 5 thread applications, coverstitch, chain stitch etc. When in use the serger requires a different looper cover (table). This looper forms the stitch on the underside of the fabric. Some call it the locking stitch for coverhems. Depending on how many needles are in use, a different stitch will be formed on the underside of the fabric. On the right side of the fabric (top) it will look like stitches done on a conventional sewing machine. So, sometimes you will serge with the fabric wrong side up so that the formed stitch is on the right side of the fabric. (Not easy to explain.)
Depending on the brand of serger it may be threaded last. Always check your manual for threading sequence.
Thread BREAK (4 thread)- if you want to re-thread only the looper thread that broke - it requires patience. First remove the threads from the eyes of the needles. They love to tango with the looper threads underneath- where you can't see what they are doing. After you have re-threaded the looper, then make sure that the lower looper thread is sliding off the upper looper without forming a knot. You can do this by turning the handwheel to check. If ok then re-thread the eyes of the needles. But test on scrap fabric first - you will be glad you did.
Thread BREAK (5 thread) - remove the thread from the eyes of the needles if you are re-threading the looper. They love to Tango TOO. Then thread the looper and then put the needle threads back in the eyes of the needles. Here's looking at you!
NOTE - for testing tension for different stitches - you can put different color threads in the different positions. Use the same color as is on the serger for best results. It goes without saying you should use the same weight thread that you will be using for your project. :-)