I've got a Necchi 535FA with a bobbin thread that doesn't hook.

Hm, I'm not able to locate a manual but may be able to offer some suggestions.

Remove the top thread from the machine.
AVOID OLD OR BARGAIN BIN THREAD!
Use the same thread in top and bobbin.
Be sure to use a brand new needle--needs to be compatible with the thread and fabric of the project..
ALWAYS RAISE the presser foot and rethread from the beginning.
Set the top tension to the midway point.
Verify the bobbin is loaded and threaded correctly and it turns the correct direction.
Pull the bobbin thread up through the fabric before taking the first stitch. It also helps to hold both thread tails in your left hand when taking the first stitches.
Test your machine and tweak the top tension until the top and bobbin threads meet in the middle of the fabric. (Increased top tension will pull the bobbin thread up. Decreased top tension will allow the bobbin thread to pull the top thread down.)

How to Thread Necchi Sewing Machine

How to Thread Necchi 535FA 535 534FB 534 Sewing Machine and Bobbin Case (not your model, but the threading and basic instructions will be similar or the same as your machine)

How to thread Necchi model 535 FA sewing machine now with captions

This is a normal problem for all sewing machines. It is called timing. While the needle is on it's way to the needle plate the thread is picked up by the hook(sharp, under bobbin). If the hook and needle aren't in the right position the thread won't be picked up. Open up your needle plate and use your hand wheel while you watch what happens with the upper thread as it rises. You should notice where the hook is while the needle is rising. There are are other times that the needle thread isn't picked up and that is when the hook isn't close enough to the tip of the hook. Now, you must go to you tube and learn how to time your machine. If this isn't something you wish to take on you can take to your local repairman.

try changing the needle
also try rethreading the machine top and bobbin
make sure the bobbin is turned the correct way in the bobbin case
if the suggestions don't help then it's possible that the machine
needs to be checked for a timing problem

try changing the needle to see if that helps
if it doesn't,, then I suggest that the sewing machine be checked
at a repair shop to see if the bobbin case needs to be replaced and
to see if the hook and the hook race need to be replaced

Timing is out...probably due to a recent jam...this is an overview.http://www.sewusa.com/Sewing_Machine_Repair/Sewing%20Machine%20Hook%20Timing.htm

Serviced more than 2 years ago ??
Overdue

Hi, I've got a necchi sewing machine too, not the same model as yours.
you said you were sewing denim & the machine jamed & bent the needle, it's sounds like the machine is out of time, sometime it doesn't take much to get them out of time & would have to be serviced by a repair shop with the tools needed to fix the timing.

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.

Hi - I have a 510 Necchi sewing machine - how do a fill the bobbin?

- check ifu are using same needle model.
- check hight of needle bar is ok
- check timming between needle bar and hook.
- check if your material is very stritch or no
- check blad point of hook is ok or no
best regards

From the reel pin take the thread to the left and over the top thread guide above the takeup lever, make sure the takeup lever is up and and make sure the presser foot is up, take the thread straight down and round the right hand side of the tension unit and back up the left hand side to the takeup lever, thread the takeup lever right to left and take the thread down any guides to the needle, if the bobbin case goes in the front thread the needle front to back, if the bobbin case goes in the side thread the needle left to right.