Juki Serger - MO-50e thread will not move out of the machine and continues to tangle under the needles. Please help! The machine worked beautifully for a few hours and now it is a really expensive p

Be sure you are using a needle size suitable for the thread weight you are using.

Try this method for threading needles:
Lick your index finger and swipe it across the back of the needle eye.
Aim the thread cut end above the needle eye and slide it down to the eye. It should go right through the eye.

Are you sure it's a 5 thread?
I looked at the threading diagram on the 804 and it appeared to be a 4 thread. It looked like an overlock with a safety stitch in the center.
The 5 thread looked like the number was an 814

Most likely. Most overlockers can make a rolled hem. You will probably want to do a lot of practicing on scrap chiffon before trying it on the real thing. It involves using only one needle, both loopers, and making appropriate adjustments to the machine.

Serger 101 Threading the Juki MO 654de Machine for Roll Hemming by CKC...

How to Serge Rolled Hem

Serger Stitches 101 Cheat Sheet Never Ever Without It Your New Must Have...

Bernina has some very nice Serger Workbooks that could be helpful:
Bernina Mastery Workbooks

-50E:
http://www.manualslib.com/products/Juki-Mo-50e-3293782.html

-51E:

Juki MO 51e Manuals

Make sure you are threading the machine correctly. Make sure you are using serger thread that isn't old. Make sure you are undoing all the threads when it breaks and thread it from the beginning.

Make sure you have the right needles in their respective places. My Juki MO has two different size needles.

Have you installed new needles recently? Also, sometimes old thread causes a problem,. Or the needle size/thread size are not compatible.

How to Thread Juki MO-134 Serger from watching lady at Lyles. Turn upper blade up. Push in first then turn up.It makes threading easier. Blue Thread upper looper first. Pull thread through tension knob. Don'tjust lay it there. (She thought that is what I must have done) Orange Thread lower looper next. Pull thread through tension knob as inthreading upper looper. Adjust lower looper so it is right nextto upper looper so that their points are almost together and directly belowsewing needles. Lower looper will be in front of upper looper (I believe). With tread from upper looper pulledback, slightly lift lower looper above upper looper and thread. I think this isright. Pull thread back with other thread. Tension is the key. Remember that. Yellow: Thread left needle first.Remember tension. Pull thread through curled wire on left side of needle arm. Green: Thread right needle. Rememberabout tension. Pull thread through curled wire on right side of needle arm. b> Note: Before sewing turn the wheel tomake sure the stitches are going together correctly.

You can download a free threading guide here - http://www.sewusa.com/Threading_Diagrams/Threading_Pages/Juki_Sewing_machine_threading/Juki_MO_644_Threading_Diagram.htm

The same site also sells manuals.

Threading Tips:

Have the thread antenna at it's highest position.

Set the tensions to zero.

Have the presser foot up while threading.

When you thread a serger for the first time, or if you are having a threading problem, use a different color thread for each guide. This can quickly indicate where the problem lies.

Once the stitch is satisfactory, change to the color you prefer - but this way is the easiest - cut the thread near the thread cone and tie off with the new thread. With the tensions at zero, slowing run the serger until the new thread appears. You will need to stop as the knots approach the needles and thread them by hand.

Do the tie-off before running out of thread and this will save a lot of time and stress.

Open the font of the serger and the instructions will be printed on the serger or on the door.

Raise the presser foot and set the tensions to zero when threading.

Turn the hand wheel so the upper looper (curved one) is at it's highest point and thread it first, and then the lower looper.

With some sergers you must thread in a certain sequence. This should be indicated in the instructions on the serger.

Set the tensions back to normal ( 4 - 6), lower the presser foot and run a length of stitching to see if the threads are knitted together as they should before you start serging your project.

If you mean the threads get tangled behind the presser foot then maybe this can help. Try pulling the threads gently as you guide the fabric through the first time. Also, I sometimes put a scrap piece of fabric under the presser foot with the edge lined up with the needles (so it is further back than normal). Then I gently press the speed control foot and pull on the threads. This allows the needles to start sewing right away on the fabric rather than giving the thread a chance to get tangled. Hope that helps!