Sat in front of the new to me necchi and can't find a manual for how to thread and set it up, keep breaking needles any help please

Yes quality of thread could definitely affect sewing, as will a blunt/old/wrong size needle for the material used. Also must have same thread in bobbin and needle also corect thread and needle size for material sewn plus correct tension for that material too. Could be lint or tangled threads underneath needle plate too.

Search the internet for:
Manufacturer + Model + the word "Manual"

or search YouTube videos for "sewing machine threading." You may not find your exact machine, but many machines have similar threading patterns. Be sure to raise the presser foot before threading the upper thread so it will seat properly in the tension disk.

If the thread is breaking at the needle, it could be several problems:
Threaded incorrectly--#1 cause
Upper tension too tight
Install a brand new needle compatible with the fabric & thread
Make sure the thread is not too large for the needle eye
Avoid old, fuzzy, bargain bin thread

All About Needles

...

There are a number of things that could cause this.
Needle installed with flat in the wrong direction.
Excessive thread tension,top or bottom.
Lack of lubrication. If the machine can do anything more than a straight stitch the mechanism can gum up and not move the needle correctly.
Here is a link to threading directions.
Necchi 3537 Sewing Machine Threading Diagram

There are many possibilitys

1- the needle and the fabric have to match - soft needle to hard fabric and the needle breaks - you need a needle with a higher number ex.90
2- not threaded correctly
3 - thread tension is too High to the fabric

look in the manual
good luck

The top 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

8. Try a different spool or cone of thread

on my 2 necchi's,, I put the needle in with the flat side to the back
of the machine.

here is 2 links for a manual

http://www.sewingpartsonline.com/instruction-manual-necchi-574fb-download.aspx

http://www.sewingpartsonline.com/instruction-manual-necchi-574fb.aspx

Good day!

please try this simple tips:

Good day!

A sewing machine operator can often help themselves when their machine does not operate properly.
Here are some simple instructions, which if properly used can save time and mechanics service calls.
TROUBLE;UPPER THREAD KEEPS BREAKING;
This could be trouble;================Do this;
1.Top tension to tight================loosen tension 1 turn
2.Machine improperly threaded=========check threading
3.Thread twisted on guide post========"
4.Thread twisted out of tension======="
5.Take up spring bent or broken=======Check action of spring
6.Thread jumped off pull off finger===Check threading
7.Needle bent or burred===============new needle
8.Bad cone of thread==================try another cone
TROUBLE;LOWER THREAD KEEPS BREAKING;
1.Bobbin tensionspring to tight=======Loosen tension slightly
2.Bobbin threaded wrong===============check threading
3.Bobbin wound to tight or uneven=====try new bobbin
4.lint or thread on bobbin case=======clean inside case
5.Lint or thread inside hook==========clean inside hook
6.Bobbin case nicked bent or burred===check/change case
TROUBLE;MACHINE STARTED SKIPPING STITCHES;
1.Needle bent or burred===============change
2.Needle set in crooked===============Check
3.Thread jumped off take up spring====check threading
4.Thread jumped off pull off finger===check threading
TROUBLE STITCHES SHOWING LOOPS;
1.Forming loops on top of cloth=======Tighten bobbin tension
======================================or loosen top tension.
2.forming loops on bottom of cloth====Tighten top tension
3.Bobbin placed in case incorrectly===remove and replace
4.Bobbin thread slipped from under====check threading of
tension===============================bobbin case
5.Lint or thread in top tension=======clean between tension discs


Thank you and good luck.

Change the needle. It sounds as if it has been damaged and bent.

The most common reason is the needle not inserted correctly (backwards), other causes can be burrs on the needle plate opening or burrs on the parts in the bobbin area.

Usual causes are:

Weak or inconsistent thread..

Threaded wrong.

Needle installed backwards or not seated.

Incorrect tension or contamination in the tension control.

The key to finding the problem is to manually turn the machine through cycles and watch at what point the thread breaks or is strained excessively.