Left needle stitches not being caught by looper

Start with the threading sequence. Upper looper, lower looper, left needle, right needle. Your upper & lower loopers must be threaded before your needles or it won't make the stitch. If it still doesn't work, it's out of time and will need to be taken in to a shop.

It appears that there are two issues: skipping stitches, and, loose stitches. Let's deal with them individually but first some general points to check.
1. Change both needles for completely fresh ones out of the package. Make sure that they are inserted all the way up, this is very important. The right needle should appear longer than the left one. Make sure also that you are using the correct needles for your serger.
2. Use a good quality thread with very little stretch, almost no fuzzies, and in pastel colour. Dark thread ages quicker, therefore has a shorter shelf live. A good quality sewing machine thread is also acceptable.
3. Make sure that the tension dials are clean and free of lint or other debris.
4. Re-thread the serger in this order, keeping the presser foot in the down position at all times
a) Upper looper. Ensure that the thread is securely embedded inside the tension discs. Place the thread tail under the presser foot to 11:00 o'clock and place the presser foot down again
b) Lower looper. This is the difficult one to thread but make sure that all the thread guides are properly threaded as well as the upper looper elbow. Check that the thread is lodged between the tension discs. Once the lower looper eye is threaded, place the thread in front and over the upper looper and then under the presser foot to 11:00 o'clock and place the presser foot down again.
c) Right Needle. Thread the right needle path, again ensuring that the thread is between the tension discs. Place the thread tail under the presser foot to 11:00 o'clock and lower the presser foot.
d) Left Needle. Proceed as with left needle.
e) Double check that all tension dials have their respective threads embedded between the discs by pulling firmly up on each thread above the tension dials.
f) Check that the stitch length is set to between 2.5 and 3.0, differential to normal, blade position to middle, blade is engaged, and upper looper converter not in use.
g) Set tensions to recommended setting for 4-thread overlock.
g) Make a test stitch out. How is it? Still having the same issue/s?
If yes, continue with the items listed below, otherwise have a great time serging.

Skipping Stitches:
1. Check that the looper tips are smooth. Burrs will cause problems.
2. Check that the needles match the type of fabric being sewn.

Loose Stitches:
1. Double check threading.
2. Debris caught between tension discs will also manifest itself in loose stitches. Take an 8" X 6" piece of medium weight clean and lint free cotton fabric, fold it in half length-wise and pass the fold only firmly between the tension discs from top to bottom (with the presser foot up and no thread in the tension dials).

Re-thread and test stitch. How is it now?

Assuming that your rethreading specially the upper looper and the lower looper threads tension is accurate, and still problem in getting the left/right needle to stitch then most likely looper/thread timing is out. This will need your local technician to do the adjustment.

no, you need the blade in place and cutting to give an even cut fabric edge. Set up for a three thread using the right hand needle, take out the left hand needle. move blade over to the right so it is cutting wide. Most overlockers there is also a thread finger you need to change on the foot, or a little lever you flick to move this finger forward into the stitching area. Check this on your manual as each make is a bit different.
If you can source it, put wooly nylon thread into the upper looper (knot it onto existing thread and just chain it through, the knot should go through the looper eye fine). Now turn the tension on top looper down so it is looser and tighten up tension on bottom looper, so needle 5, top looper 2 and bottom looper about 7.

Now test serge, the fabric cut edge should be wider than the overlocking seam so the fabric rolls under inside the stitching. Adjust the two looper threads so that this is happening, you want the bottom looper thread to nest right up against the needle stitch and the top looper thread to wrap all the way around too.

Once you've got this happening, turn the stitch length down to 0.5, to close the stitching right up. On some fabrics you'll need to adjust the differential feed too if the fabric is "waving" a bit.

Uneven stitches or sometimes loose when serging could indicate that one of the tension devices is faulting, so if this machine is not new and its doing this, it could need a service. Can you get a regular smooth three or 4 thread seam out if it???

It is always good to just recheck the threading path, make sure the thread aerial is up and that a thread hasn't got caught back on the thread stand somewhere if you're getting something wonky happening, threads stream off overlocker cones through the machine so anything wrong in the thread path will throw off the stitching.

left one, rolled hem is usually a narrow seam so you remove the left needle, change the needle plate or flick a switch that changes the position of the thread finger under the foot and tighten up the looper tensions. You want the top looper thread to go around to underneath and the bottom looper thread to disappear against the needle stitching. You also need to close up the stitching density, by decreasing the stitch length.

One critical hint:

You must thread the loopers BEFORE the needles, otherwise it won't stitch. Begin with upper looper, lower looper, right needle then left needle.

I was having this very same problem with my lower looper . I had been using the one needle stitching all afternoon and I was doing quite nice stitching. then I decided to put the right needle back in and do some overlock stitching and guess what I spent the next two hours fighting the looper problem. I had completely re-thread this machine at least 20 times now. I decided to take the needle out and re-insert it and re-thread it one more time (right lower looper- then upper looper- right needle- then left needle) was careful to pull all threads to the back and under the presser foot for about 6 inches.
Held on to the thread, lowered presser foot and did the chaining stitch. BINGO it didn't break, tried it with a piece of cloth and Perfect stitches. I have a Babylock BL402 and used tension settings left to right
4-3-3-3 and default settings for the rest.
Hope this helps someone someday.
Jo Griffith

I have just learned this :)
Either needle thread may be engaged for 2-thread serging.
1. Open the front cover and cutting blade cover, cut the upper looper thread just above the threading guide ( this is plate that has two holes for the threads) Raise the presser foot and pull out the clipped thread from under the foot. Remove upper thread from the machine (or you can leave the cone thread on, it doesn't matter).
2. Rotate the handwheel to bring the upper looper to its lowest position.
3. Rotate the subsidiary looper up and to the left, then slip the end into the upper looper thread eye from backside.(this sounds complicated, yes? but it is very simple : the looper has a counter part that is spring-locked to move from left to right and right to left. This is the little claw-looking part of the looper that when in the postion to serg with four threads is to the right side of the looper. It looks like a scorpion's tale. If you can't figure which part it is, use your finger to probe the looper and you'll feel it give a little. This part needs to be moved to the left - it will not slide over, but swing up and over and down, like an arch. Then, where the thread comes out of the looper is where you want the little claw-like part to hook into.)
4. Close the covers. Decrease the needel tension - this depends on what the stitch length is. Stitch length: 2-3, stitch width: 3.0 = L needle n/a, R needle 1; upper looper n/a, lower looper 5
stitch length: 2-3, stitch width: 5.0 = L needle 0, R needle n/a, upper looper n/a, lower looper 3.5

Those are for a flatlock stitch - for a 2-thread rolled edge :
Stitch length: 0.5, stitch width: M = L needle n/a, R needle 4.5, upper looper n/a, lower looper 3.5
Stitch lenght: 1.0, stitch width: M = L needle n/a, R needle 4, upper lopper n/a, lower looper 3.0

If you have any questions, e-mail me at [email protected]

Solution taken from "Handbook for Huskylock Sewing Machine Models 1001L/1000L/1000"

1. Raise the presser foot by using presser foot lever. When the presser foot is raised, the two thread tension discs in the thread tension control panel are released so that thread passes freely between them. Otherwise thread tension may not be correct.

Important! When threading the needle, always be sure to lift the presser foot lever, and also take care to thread in the proper order.

Threading order:
1. Upper looper thread (green)
2. Lower looper thread (blue)
3. Double chain stitch looper thread (purple) in case of 5 thread stitch or double chain stitch
4. Right needle thread (red)
5. Left needle thread or double chain needle thread (yellow)

Caution!
Because the left thread tension dial (yellow) is used for either the left needle or the double chain stitch needle, these needles will never be used at the same time.

Upper looper (green) sequence:
1. Thread holder (silver triangle openings attached to thread holder stand)
2. Thread guide (flat silver clips just behind thread tension disc)
3. Thread tension disc (circular knobs with numbers for tension setting)
4. Pull thread around upper looper guide and upper looper
5. Pull thread into hole of upper looper

Lower looper (blue)
Repeat 1, 2, 3.
4. Pull thread around guide (see color coded chart inside front serger cover).

Easy threading mechanism (for lower looper)
1. Pull out the lower looper threading lever
2. Thread the lower looper and position the thread on hook of the lower looper
threading lever.
3. Push the lower looper threading lever back to its basic position while
holding the end of the thread.

Caution:
When returning the lower looper threading lever, always make sure that the two
blue triangle marks (directional arrows) meet each other.

Right needle thread (red)
Left needle thread (yellow)
Important: Thread the needles after threading of lower looper and upper looper.
First raise the presser foot lever, and then thread the needle threads in order shown in color coded thread guide.

Most likely is the left looper thread is trapping the needle threads.

Remove the threads and start over in this sequence....

Left looper - right looper - left needle - right needle.

If you thread the needles before the lower looper, the needle thread wrapped over the looper will be under the looper thread and will never be free to form a stitch, so the threading sequence is critical.