How do I replace an upper looper on my janome serger?

Best advice would be to consult your owner's manual. The most common serger problems are caused by incorrect threading or not threading the threads in the proper order. With most sergers, the upper looper should be threaded first. The lower looper is threaded second and the lower looper thread tail should drape OVER the upper looper. Then thread the needles.

Be sure when threading that each thread is pulled snugly into the tension disks.

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this is a domestic machine mechanic issue due to part replacement

I don't have a Janome, but you might check your threading to see if it's correct, lucky you to get a new one!!!

Sergers are funny things. You can certainly try just replacing the needle.... make sure you thread correctly. upper looper, lower looper, right needle left needle... etc.

Before you take off sewing... run the machine by hand a few revolutions if it seems to be moving with no more clunking etc. try to sew. If it breaks the needle again. Stop immediately and take it in.

it sounds like the serger needs to be checked to see if it's out of
time, at a sewing machine shop

Hi
There are a partial manuals available for Janome Magnolia machines available on their site.
http://www.janome.com/documents/File/ManualFile/Inst%20Book%207034D%20(English).pdf
The tension settings are included on page 27 of the manual.
Hope this helps!

I can share the information for my BabyLock Imagine in hopes that it will help you.

There are options of 2 or three threads.

For the 2 thread the serger must have a 2-thread converter- aka, auxiliary looper or subsidiary looper.

This is a spring type mechanism that fits in a small hole at the top of the upper looper. It 'tricks' the upper looper into thinking it is threaded. It must be engaged by connecting to a small hole in the upper looper

Set up the serger for a 2 or 3 thread right or left needle.

Stitch width - wide if you are using the left needle and normal if for the right needle; length 1 - 3mm.

Needle tension loosened and looper tension normal.

Disengage the cutting blade..

Set the differential feed at normal.

Hope this will help.

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 suggest you get a tech to re-time your machine. timing is complex on an overlocker and if not done correctly you will probably break a looper.

scott.

The order of threading is most important. If you letter the tension knobs from left to right A,B,C,and D. The order for threading it is C,D, B, A. There are two arms under the needle that cross each other called loopers. The order is upper looper, lower looper, right needle, left needle .I'm sure there is a diagram under the cover when you open it. Most do. It would be very helpfull to use a long threading tweezers to guide the thread through the holes. The lower looper has a hole in the back to put the thread through then through the front hole ( though some newer sergers have a lever that you put the thread on and it does it for you and over the thread of the upper looper and out the back.
It would help alot more if I knew the brand and model of your serger so these are basic instructions. Hope I helped.
Rick