Question about Janome MyLock 634D Mechanical Sewing Machine

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Lower looper I have threaded my machine properly, I think, but the lower looper keeps coming unthreaded. I have rethreaded about 10 times very carefully. each time it lock stitches for 1 second and then stops. The strange part is that the thread appears able to escape from the needle hole without breaking. The machine works for about 1 cm and then no longer "braids" the threads. they just string along getting longer at the back of the machine

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  • marly Oct 05, 2007

    marly here: I found that i was not threading the lower looper thread through the two threads that circle under the lower looper needle. i assumed that it would thread itself through the proper way once it was running but each time it would not work, so when i took the tweezers and loosened the other threads enough for me to see and thread through them, it worked first time. but i had threaded before at least a dozen times, but obviously not tight against the needle to pass between the other threads. (this is hard to explain , I hope this is clear enough for someone else with the same problem.}

  • miss popsi Nov 05, 2007

    i too have had this very frustrating de-threading occur... i need help as 5cm of overlocking and then no braiding leads to much hair pulling!!!

    i will try marly's solution but not quite sure of the exact process

  • Povs Nov 07, 2007

    I too have the same frustrating problem with the no 1 lower looper breaking as soon as it has sewn a very short distance. It can take hours of rethreading to get it to work. It is a very good maching when it is working, but half the time it is unusable. This appears to be a design flaw. Can anyone help?

  • Anonymous Apr 19, 2008

    my lower loop is too loose and it gets jamed in the feed dog. the thread come out easily.



1 Answer

It is impossible for a looper to come unthreaded if you are holding one end and the other is still feeding off the spool. Somewhere a thread broke - must be either the upper looper or the needle. Try completely re-threading your machine. Many machines have an "order" they prefer to be threaded. Try starting from the right tension guide and work to the left.

Posted on Oct 04, 2007


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2 Answers

My Jancome 7933 will not make any stitches

Try installing a brand new needle.

Sergers are very finicky and if they are not threaded absolutely perfectly, they will show their attitude.

Remove all the thread from the machine. ALWAYS Raise the Presser Foot and rethread from the beginning. Make sure to thread each thread in the correct order (usually, upper looper, lower looper, then needles). If you don't get the threads in the proper order, it will most likely not work. Be sure that the thread paths are correct for all threads. Give each thread an extra little tug when going through the tension disk to make sure it is seated completely. Pull all the thread tails under and out the back side of the presser foot before beginning to stitch. Set the tension disks to the midway point between high & low number (this is the factory standard, although each machine may require some adjustment).

Test your machine and hopefully you will get a chain stitch.

Also, if a thread breaks or comes unthreaded, it is usually best to unthread totally and rethread from the beginning.

If that doesn't work, it is most likely a timing issue where the needles & loopers are not arriving at the correct time to connect. Probably requires service.


Jul 21, 2016 | Sewing Machines

1 Answer

Forming stitches beautifully, but not on the fabric

Be sure to RAISE the presser foot when threading the machine so the tension disks are open to accept the thread. It also helps to grasp the thread between the thread tree and the tension disk and with the other hand grasp the thread below the tension disk and give the thread a little tug to make sure it is seated all the way in the tension disk.

Of course, make sure that the machine is threaded in the proper sequence--check the owner's manual (usually the upper looper is threaded first, then the lower looper and the lower looper thread tail is draped Over the upper looper in the last step before being pulled under the presser foot).

If the thread breaks or comes unthreaded, Best Course of Action is to remove all the threads and rethread from the beginning. Nine times out of ten, trying to rethread one thread will not work!

Also, when removing thread, it is not a good idea to clip the threads between the thread tree, raising the presser foot, and then grabbing the thread tails at the presser foot and pulling all the thread ends down. Threads should not be pulled UP through the tension disks.


Feb 22, 2016 | Sewing Machines

1 Answer

Just bought Juki MO1000. Have threaded and re-threaded several times (easy enough) because the lower looper thread (position 1) thread breaks after sewing 4-5 inches. Any ideas?

Yep, 9 times out of 10 when thread breaks, something is not threaded correctly. Also, whenever thread breaks or becomes unthreaded, best policy is to unthread everything and start over from the beginning. Simply re-threading the broken thread will usually not work.

Remove all the thread from the machine. RAISE the presser foot (important to ALWAYS do this so the threads will seat properly in the tension disks).

Rethread totally from the beginning making sure to follow the threading instructions for each thread and that the threads are threaded in the ORDER (ie upper looper, then lower looper, then needles) per the manual. If the threads are not threaded in proper order, the machine will most likely never work.

When threading the lower looper, as the last step, be sure to pull the thread tail over the top of the upper looper mechanism before pulling the thread tails under the presser foot.

If the thread continues to break, make sure the tension for that disk is not set too tight. Loosen it up and see if that makes a difference. Most factory standard thread tensions are around the midway point between the high and low numbers. Then slight adjustments can be made from that setting to tweak the tension result.


Jan 29, 2016 | Juki Sewing Machines

1 Answer

Thread broke on bottom looper the first time out of box i had to try and thread and the tension was still tight The bottom threads were not stiching

I'm going to assume here you're talking about a serger. Unthread the lower looper and the eyes of the needle. Set the lower looper tension to 0. Rethread the lower looper, then the needle eyes. Then reset the lower looper tension (try about half a number lower) and see if it chains. If it won't chain, try replacing the needles.

Mar 17, 2014 | Janome Sewing Machines

1 Answer

Thread breaking at loupers on overlock machine singer

If it's the lower looper thread breaking, the cure is to unthread the eye of the needle(s), rethread the lower looper, then rethread the needles. Sergers have very specific internal crossings that are easiest to do if the various parts are threaded in a particular order. Typically, you thread the upper looper, then lower looper, then the needles. If you try to deviate from that without knowing exactly what you're doing, it tends not to work well.

In general, most serger troubles, especially for beginners, trace to minor misthreadings. It's easier, in my opinion, to rethread the entire machine from scratch than look for the minor error that's catching you up. And you learn the threading pattern well as a special bonus. <g>
If it's not cureable by rethreading a couple of times from scratch, the next thing to do is put in new needles, right way around, and rethread again.

Feb 08, 2014 | Singer Sewing Machines

2 Answers

Why does the 4th thread keeps breaking on my serger? I've re-threadedi it a dozen times carefully following the diagram. What am I doing wrong?

Most likely it is either your tension on thay thread being too high, or the needle is too big for the project you are working. Lower that tension, use the next size up needle, and thay should fix it. Also, I STRONGLY suggest only using maxi-locks thread. They are more expensive than other serger threads, but they are always half-price at hancock... Any other thread I have tried using causes breakage, especially on the the lower looper (the 4th thread). Although, of you keep the tension low-below 3 or so, you should be ok. If these tips don't help, I would also check your cutting width, if your machine has an adjustable one. If it is leaving too much gabric to the right of the needles, out is conceivable that this is putting too much pressure on the threads. Let me know if this helps!

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1 Answer

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Hi,...if the lower looper thread is breaking before you sew six inches or more then I suspect a threading problem.When the lower looper thread breaks, You MUST unthread the needles before you thread the lower looper. Thread the looper and then rethread the needles.

Hope that helps,

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I had to rethread my Singer Ultralock serger and now it won't sew correctly. Best I can tell the lower looper keeps coming unthreaded, but this doesn't happen until I put material in. I have rethreaded it...

I had read where someone said their lower looper tension dial had pulled apart. Sure enough, mine had too. We snapped it back together and Voila problem solved!

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1 Answer

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Unthread the needles, rethread the loopers properly, then rethread the needles. Make sure that all four threads are pulled securely into the tensions and retry.

The loopers must always be threaded before the needles or it will not chain.

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