Why does my Janome MB4 Jump in mid pattern and finishe 1" up or down?

Try page 24, although it may be referring to something else. Such information like hours used is only available to a technician using factory computer software.

https://www.janome.com/siteassets/support/manuals/embroidery-models/inst-book-mb-4en.pdf

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A nice satin stitch is set when the zig-zag threads touch but do not overlap the previous stitch. It is a matter of finely manipulating the stitch length to accomplish this goal.

Sewing Perfect Satin Stitch Wildly Wonderful Wearables Patterns Notions...

How to Sew Satin Stitch

How to Do Satin Stitches on Regular Sewing Machine

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&ved=0ahUKEwiV_b7QwsLTAhVQ7WMKHRSfBbAQFghyMAc&url=http%3A%2F%2Fmachinequilting.mqumag.com%2Fwp-content%2Fuploads%2F2014%2F12%2FSatin-Stitch-Techniques-Part-1.pdf&usg=AFQjCNFXYKp2C-RJEAAUMWwApqZlU895uQ&cad=rja

Computerized sewing machines generally do have a stitch count or hours count or both. However, usually a technician is the one who would know how to access that. You might want to try contacting a local dealer's tech and asking if they would help you with that. However, realize that they may not be happy you are buying a machine from a private party than through their dealer store.

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are you using a good thread and the same thread on the top and in the bobbin, different threads will sometimes act up. I also can not sew one brand of thread on my machine, try Mettler or gutermann's you can get them at JoAnn's or Fabricland. hope it helps good luck K

This is a sewing machine we don't have in the US, so I'm guessing here, but I think the stitch pattern is unbalanced. On some machines, there's a dial to "balance the patterns", which you can turn to restore symmetry to something like a buttonhole. Often you need to automatically stitch out a pattern in order to reset the balance knob.
If your machine doesn't have such a knob, it's time to take it in for a lookover.

Hi Morehu, this Youtube video will help you with your problem:

https://www.youtube.com/watch?v=tICJdFZ7IxY

Although you have selected a zigzag have you also set the stitch width and length manually as required? Some stitch types have restrictions on the width you can set so it's important to know which these are.If you don't have the instruction book it is available as a free download from Janome. Go to www.janome.com, click on the Machines tab then choose 'retired' and scroll down until you find the 6125QC - the link to the user guide is in the top right corner of the specifications tab.

First make sure you have a good quality cotton thread. I like to use Mettler silk finish 50 weight natural color. Start by sewing a straight stitch on two layers of light cotton fabric. You should have a tension the looks the same on both sides of the fabric when you sew. Adjust the tensions, if nessesary, and then try a sample on a practice sandwich. You might have to increase the top tension just slightly.

Right, now I've figured this out :)

Put your button in the holder on the foot - fiddle about with it enough and I'm sure you'll work out how, one bit slides open and then you can close it again to hold the button.

Then fit the foot to the machine - the piece with the button in goes at the back.

Select 2 on the stitch selector, 4.5 on the stitch width and buttonhole on the stitch length.

Using scraps make up a piece of fabric with the same number and construction of layers as your finished garment and do a practice run or three.

You can set the actual feed length using the -.+ control (beside the feed release switch at the front, below the sewing table).

Between button holes you need to reset by turning the stitch selector wheel slightly until you hear a click.

Once you're happy with the method, think you have the settings as you want them and feel you have done enough practice try it for real on the garment.

Note: the button holes come out a bit long - just don't cut down the whole length or you may need to hand sew them tighter.