Question about Juki MO-644D Mechanical Sewing Machine

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MO -634 mechanical sewing machine problem

My sewing machine is a 4 thread machine and it dosn't have agood sewing results when you try to sew in it.

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Re: MO -634 mechanical sewing machine problem

What does "doesnt have good sewing results" mean? Is the stitch loose? Does it skip stitches? is the tension balance off?

The serger "It doesnt sew right" rule of thumb: replace your needles, make sure they are inserted all the way into the clamp (one will be hight then the other) and orientated properly (eg. flat to the back), COMPLETELY unthread machine, re-thread!!!! re-thread!!!, check for proper threading (make sure thread is in tension discs if possible), change your thread.

Improper threading is the #1 problem causer. I cant stress it enough. Rethread Rethread Rethread!

Posted on Jun 27, 2008

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I have a brand new Juki MO-50e and the threads are loose on the back of the fabric, how do I fix this?

  1. . re-thread your machine with a rainbow of colors. (important that you remove the existing threads if you are not sure it is threaded properly.) make sure you are lifting the presser foot while rethreading.
  2. Sew a good 6 inches.
  3. Look to see which threads are the offenders and tighten the co-responding tension knobs a little.
  4. Sew another 6 inches. Examine the result. Adjust tension again if needed.
  5. Work this way until you have the stitch balanced.
  6. Finally when your stitches are perfect. clip the threads at the spools in back. And tie on the coordinating colored thread for your fabric.
Get used to this procedure since it is common to have to adjust tensions when you change fabric. Good luck!

Oct 23, 2014 | Juki MO-644D Mechanical Sewing Machine

1 Answer

Right needle will not stay threaded and sew

try using a longer thread tail of 4 to 6 inches, that what I do & my
needles never come unthreaded

Aug 12, 2012 | Juki MO-644D Mechanical Sewing Machine

1 Answer

Need user manual for mylock 634


You can view and download the instruction manual in PDF format by clicking this link.

For further details and videos, click here

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Jul 20, 2010 | Janome MyLock 634D Mechanical Sewing...

1 Answer

I have Juki MO-644D It has been working very well untill now

have you got the solution to this, cuz mine is doing the same... :/

Jul 10, 2010 | Juki MO-644D Mechanical Sewing Machine

1 Answer

Do you have a quick threading guide for this

Could not find. Here is one for the 634 that may help -

Raise the thread antenna and loopers to their highest position.

Set the tension controls to zero before threading.

Many sergers have the threading diagram inside the front door of the serger.

Apr 01, 2010 | Juki MO-654DE Mechanical Sewing Machine

1 Answer

How can I use this machine as a MERROW machine ?

For best results, use Maxi-Lock cone thread.
Remove the left needle.
Slide the stitch forming finger towards you, away from where the stitch forms.
Set the stitch length to around 1.
Set the needle tension 4 or 5.
Set the upper looper tension at 4.
Set the lower looper tension at 7.
Adjust the stitch width, if needed.

Jan 24, 2010 | Juki MO-644D Mechanical Sewing Machine

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