Juno (Janome) Serger thread not interlocking?

Could be the result of several things. There could be some gunk or threads stuck in the tension disk. Be sure to remove the thread and rethread from the beginning in the order specified. ALWAYS RAISE the presser foot when threading!!!! If you haven't tried a brand new needle, do so, and make sure it is pushed all the way up and installed with the flat side facing the correct direction. Some machines recommend #90 as the largest needle to use. Also, perhaps the needle eye is too small to accommodate the thread. Watch where the thread is breaking to give you an idea of where the problem may originate. Try a different brand of thread. Sometimes black thread causes issues because the heavy dye affects the thread. Set the tensions at the midway point and then loosen the tension on that one needle. There could also be a burr or rough spot somewhere along the threadpath that is catching the thread. Last idea--could be a timing issue.

Serger needle thread breaking sewing discussion topic PatternReview com

http://www.amitymama.com/threads/anyone-have-an-idea-why-my-serger-needle-thread-keeps-breaking.280524

Make It Handmade Threading Your Serger or Overlocker

Help please Serger needle thread breaking

Sewing Machine Thread Keeps Breaking

I know this is tongue in cheek but have you got the needle in back to front.

SKIPPED STITCHES ON A SERGER
1. Is the needle bent or worn--replace
2. Is the needle inserted correctly into the needle holder--check needle
3. Is the Serger threaded correctly--rethread
4. Is the presser foot pressure right for the fabric--adjust

use a scrap piece of fabric to sew on as you adjust the tension
when the tension is to loose adjust one number higher till stitch
looks good

here's 2 links for a manual one is a hardcopy & the other is a
pdf downloadable--one is a different price from the other
http://www.sewingpartsonline.com/instruction-manual-janome-mylock-634d.aspx

http://www.sewingpartsonline.com/instruction-manual-janome-mylock-634d-download.aspx

try changing the needle
rethread the machine top & bobbin
make sure to use every thread guide
make sure the bobbin is not over wound
make sure the bobbin is turned the right way in the bobbin case
make sure the bobbin is not warped or damaged
if you've done all these things then it's also possible that the machine
is out of time & needs to be checked at a repair shop

sergers the most frustrating machines. Every time you change fabrics you go through a tension adjusting phase.

First make sure you have threaded the machine in the proper order. upper looper, lower looper, then needles from right to left. Always thread any machine while the presser foot lever is in the UP position.

If you ever break a thread... you MUST pull all threads and rethread using the proper order.

Ok that's out of the way. Pull all your threads and get out several pieces of the same fabric scrap. Thread each pathway with a different color. This will help you determine which thread is giving you fits. Sew a test strip. Which thread is loose? tighten/loosen that tension. Keep doing this until you have a well balance seam. Then clip the colored threads starting with the upper looper thread, tie off to your proper color for your seam pull the thread through and up through the throat plate. proceed in this manner with lower looper, right needle, left needle. Sew a test seam.

Good luck.

Is it possible the thread might be too old? If so, it might tend to break easier than normal. Also if it got wet.

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!

Whenever I've had an issue with threads breaking, it's usually the tension or it's not threaded right. You probably have the first thread lapping over one of the bottom threads it shouldn't be lapped over. I would suggest you put all of your tensions back at factory level, pull out all the threads and rethread the whole thing. Thread the two bottom ones first without moving the handwheel. (Make sure the handwheel has the two top needle in the up position. When you thread this machine, you must not have to turn the handwheel. If you do, you change something.) Then thread the top needles. After that hold all four threads and make a string. Test on the same type of fabric as what you're working with. Adjust tension as needed. HTH

SharonH

Once the thread breaks, the serger usually has to be re-threaded - all four components of the serger.

Raise the antenna to it's highest position.

Open the tensions to zero.

Turn the handwheel so the the loopers are at their highest position. Some sergers have a mark on the handwheel that aligns with a mark on the side of the serger for this step.

Thread according the the sequence indicated on the threading guide - this is either on the inside of the door or on the serger.