How to change stitches

If you haven't removed the top to clean and oil the cams then likely they are stuck, hence zigzag.

Doing a google search for the brand plus model number for a user guide or YouTube videos might find what you are looking for. That it is a Necchi doesn't supply the model number and of course models differ. On a 537L model, the large knob on the right side about halfway between the top and bottom of the machine adjusts stitch length. The numbers may range from 0 to 5 with 0 meaning no length and 5 being the largest length. Tension, stitch length and stitch width are all controlled by small dials on the front of the Necchi machine. If your stitch length is set to 0, the sewing machine will not feed the fabric. Incorrect tension will cause poor stitch quality. You must consult you machine's user manual to know how to adjust the tension as the procedure differs among machines. Here is a general guide, however:

How to Adjust the Tension on Sewing Machine

https://www.youtube.com/watch?v=i-7bnb_6EBU Necchi

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

It is generally the large knob on the right side about halfway between the top and bottom of the machine. The numbers should range from zero to 4 or 5. Zero is zero stitch length, five would be the largest stitch length.

https://docs.google.com/document/d/1OBOahdPrL29joIvK-_sddWvVcUuOblCc50xn2Q8eZrs/edit

http://www.sewingpartsonline.com/instruction-manual-necchi-537-l.aspx

http://www.sewingmachinemanual.net/Sewing_Machine_Manuals/Necchi/Necchi_537-L_instruction_manual.htm

Yep, thorough cleaning and oiling.


Wheel on right side that controls the needle up and down is very tight...

Will not zigzag or decorative stitches New to these newer plastic style...

...

try changing the needle
rethread the machine top & bobbin
make sure the bobbin is not warped or damaged
adjust the top tension one number or letter higher till the stitch looks normal
if these suggestion don't help then the machine needs to be serviced

It's just in the front panel, where the drawing of all the built in stitches are, it's the drawing number eleven from the left, you'll see a zig zag (red) and a straight stitch (black) Select A group of stitches (knob with the arrow) and then select the eleventh stitch (same knob but use the dial, look the manual) and then select zero on your stitch width dial. Hope that helps :)

does anyb ody have a manual i can download