I have a Juki MO 3716 and I cannot thread it. Please help. It has four threads.

Perhaps this will help:

Juki MO 2504 2514 2516 Sewing Machine Threading Diagram

there are usually multiple web sites and videos available. Just search for:

Make + Model + the words "Manual" or "threading"

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I have had this happen, check your tension on that thread and check the thread thickness. Tofix mine I recall changing both,and I think it was the thread thickness in relation to the tension

Tweezers!! The ones with the angled tips.

If you have the instruction manual, you might read the chapter which describes the proper adjustment for threads and fabrics.
If you do not have one, try to find it on eBay. It is the huge source of everything.

sewusa.com has some threading diagrams

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.

Email me at [email protected] should be able to help.

You might try on eBay items like 160431427159

Put new needles in it.

Following the colors, thread the upper looper first, then the lower looper. Next thread the needles. Always thread in this order.

I have a Juki MO 2516N. It does not have the capability to serge 4 threads. The only options are 2, 3, and 5.