Necchi 160 Overlocker/threading - Necchi Sewing Machines

Different model but it may be close enough.

https://youtu.be/UhtZ-w7oFrY

What does it do when you try to stitch or sew?

Um-hmm. Been there, done that! Hopefully, you have a manual (I'm not able to find one online).

Here are a couple of hints:

Remove all the thread from the machine.
Recommend using the colored threads that match the machine's guide--will help you figure out which thread is misbehaving.
ALWAYS RAISE the presser foot and thread each in the correct order! Check your manual, but most machines need to be threaded #3 (upper looper), #4 (lower looper), then the needles.
With each thread, grasp the thread below the thread tree and also below the tension disk and give a gentle tug. Sometimes the thread will pop when it seats in the tension unit.
The lower looper thread tail should drape OVER the top of the upper looper and thread, then sweep all threads toward the back of the machine and under the presser foot.

You might try contacting the Necchi Support service.

Look for it's manual, online.

try these sites and see if they can help you with a manual

sewingpartsonline.com--1-800-824-1192

sewvacdoctor.com--1-800-544-5858

Overlockers and or Sergers are ALWAYS threaded the same way. Upper looper, Lower looper, right needle, left needle. If you have a model number for your Juki we might be able to find you more information.

The best way to figure out tension problems is to thread each thread in a different color so you can determine which thread is giving you problems.

These machines can be frustrating and EVERY time the thread breaks you MUST start the threading problem from the beginning... upper looper, lower looper, right needle left needle.

try sewingpartsonline.com

sewusa.com has some threading diagrams

& you can also see if sewingpartsonline.com or premiersewing.com
have manual for the sewing machine

lol, why do you never get the answer you need on these sites? she clearly asked for a 150 OVERLOCKER, and everyone tags sewing machines... is there no hope? If I find an actual answer to the actual I'll come back and post it!

Just visit janomestuff.com to avail a new foot control to your sewing machine