Janome 900 cover hem needle wont stay threaded

Need more information to answer this question. "Spacer inserted"??? You mean "Double Needle"? for a 2 thread hem?
Cheers,
Embroidery Services
San Diego, CA

you could have a timing problem with the machine.

Sounds like you want to do a rolled hem for a handkerchief edge, I do the following to create a rolled hem on my over locker. Take out left needle and cut and remove that thread. Open front cover and slide back lever for the stitch finger in the needle plate, this finger stops the fabric rolling under thread tension normally so you need to pull it back out of engagement. Your Janome may have a similar means to select the rolled hem or you may need to remove the stitch finger with a screwdriver, it varies between models.

Thread upper looper with wooly nylon and right needle and lower looper in matching colour thread. (You can go wooly on the bottom looper but it hardly shows so I never bother.) Disengage upper blade and move the fixed lower blade to the right to trim less, then lower upper blade back into position. Now tension, needle leave alone (5)' upper looper very loose (2-3) and lower looper tighten up to 6-7 and test stitch. You want the upper looper thread to go right underneath and the lower looper thread to disappear against the needle stitch. And the fabric to roll inside the stitching. Finesse tensions on the loopers until this is right, you may need to change blade position too, depends on weight of the fabric and how it rolls. Once this is right turn stitch length down to close up stitching, 0.8 or even 0.5 if you want full coverage. Thats it. You can use differential feed if you want a fluted rolled edge, nice on knits.

The needle thread breaks
1. the needle thread is not threaded properly
2. The needle thread tension is to tight
3. The needle is bent or blunt
4. The needle is incorrectly inserted
5. The needle thread & the bobbin thread are not set under the presser foot when starting to sew
6. the threads were not drawn to the rear after sewing
7. The thread is either to heavy or to fine for the needle

I don't know your babylock well, some of these have automatic tensions and electronic stitch selection. But a rolled hem is achieved on any overlocker in the following way; the actual dials and knobs might vary a bit.

Firstly there is a stitch finger that you need to change or retract so that the thread can roll the fabric rather than staying flat. For a normal seam this finger sticks out in the area where the loopers and needle form the stitch holding the cut edge flat until the seam is made over it. But for rolled hems you want to retract this finger so it does roll.

On the Bernettes this is a little lever in front of the stitching area that you pull back to retract the finger. Have a look around where the stitch forms and you should see the finger. Some machines, its a part you change on the needle plate with a screw driver, or just move a switch or lever.

You want the right hand needle in place, remove the left hand needle.

Thread upper looper with wooly overlock thread, this is a fluffy nylon that pulls flat under tension but relaxes and "fills" out once its stitched into place. Gives that lovely covered look you see on shop bought tablecloth edges. Your regular thread in needle and lower looper. Usually cutting blade to the right side as you want it to cut more fabric than in the seam so it rolls under. Now loosen off the tension on the top looper, (I use 2 on mine but this is something you need to finesse with each machine), and tighten up the tension on lower looper, (about 7). Leave needle tension alone.

Now test stitch on your fabric, and finess the upper and lower looper tensions until you get the lower looper thread almost not showing, it should be right up against the needle on the underside with the upper looper thread completely wrapping around top and bottom, pulling the fabric under.a seam like this.


Test stitch and adjust upper and lower looper until this is happening.

Now, turn stitch length down to close up the stitching, probably 1 or 0.8 if you want a real satin stitch look to the hem.

Because of the stitch density this uses thread so do the finessing first, then turn the length down.

That's it! Now right down the tension settings you used and keep handy for next time.

try this solution
http://www.fixya.com/support/t9307094-cannot_get_tension_right_also_trying

not exactly your serger model but technique will be very similar for rolled hem.

You need to set up a three thread overlock with the right hand needle, (take left needle out), and change the thread finger in the throat. Sometimes a switch to do this and sometimes it is a little piece on the foot that you change with a screwdriver.

Also, this solution http://www.fixya.com/support/t9280656-thread_janome_204d_serger is basic threading on 204D, it should be very similar to your model.

I have looked for a free download instruction manual for your machine without success. But you should be able to buy one from Janome or another of the online sewing sites like www.sewusa.com or www.sewingpartsonline.com.

]ve a manual you can somtimes find them on the Janome websit
Here is a link to threading up for 334D
http://www.sewusa.com/Threading_Diagrams/Threading_Pages/New_Home_Threading_Diagrams/New_home_334_MyLock_Threading_Diagram.htm

From what I have read this manual is less than desirable. Neither is the one for the brand that I have.

You may have better guidance if you purchase and use Nancy Zieman's "Serge with Confidence". I have found it very helpful.

For the two thread rolled hem, the looper cover is used to "trick" the looper into "thinking" it is threaded.

On my serger (not a Bernina), this is referred to as a "subsidiary looper". It is a spring type mechanism that fits in a small hole at the top of the upper looper.

You use a rolled edge presser foot; right or left needle; stitch length @ normal or wider; stitch length @ 1mm for the left needle/0.5 for the right needle; differential feed @ normal; needle tension - tighten; lower looper tension - normal or looser; two thread looper cover - engaged.

Test and adjust the tension as needed before making the rolled hem on your garment.

I hope this helps.

To avoid skipped stitches on a coverstitch machine you need to use ELs (extra long) or SUK (stretch) needles and good quality thread. Poor quality thread is too fluffy and varies in thickness which can cause stitch problems. Try Maxilock thread from a cone or use maxilock on looper and regular sewing machine thread through needles and see if this improves the stitches. Also loosen off the lower looper tension to zero and see if this helps. If you are hemming around a garment and sewing across an overlocked seam then you need to minimise bulk too. lightly press the seams into the diretion you want them to sit when garment is finished, press the hem up, then force the seam allowance in the hem turnup area to the opposite direction. This spreads the seam bulk in both directions.
There is a knack to coverstitch machines but a good cover finish is quicker than twin needle on SM.

You need to disengage the cutting blade by openingfirstly opening the front and left hand side covers. pull on the larger of the two silver knobs and slide the red lever towards you. I'm not sure what the tension settings are, but I'm certain you need to reduce them a fair bit to aid in the rolling effect. I only use 3 threads when doing a rolled hem.
My description isn't too detailed but I hope it helps!

Your machine cannot do a cover stitch. Check the Brother website, they make a cover stitch only machine, it works much better than any of the serger/cover stitch combination machines, and it is a lot less money.