Need a diagram on how to threat the Necchi 6011

Often not a DIY job, as there are usually a number of other adjustments to be made. If you really want to DIY, talk to the nice folks at the yahoo group "wefixit": https://groups.yahoo.com/neo/groups/wefixit/info who can walk you through it.

Jeff: First it is never wise to put your email address in a public place like this. Second... your pictures didn't come up.

I suspect you have a shim... but not being able to see the pictures. It's hard to advise you.

try these sites

sewingpartsonline.com
whitesewingcenter.com
sewvacdoctor.com
sewingpartsdirect.com
sewingsupplywarehouse.com
sewforless.com

You can find instructions at this link. Print them out so you have them handy in case you need them again. :)
http://www.sewusa.com/Threading_Diagrams/Threading_Pages/Necchi_Sewing_Machine_Threading/Necchi_536_537_threading_Diagram.htm

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.

It is a foot that has a small square hole on the bottom that goes up and down with the needle.

TRY WWW.SEWING-MACHINE-MANUALS.COM AND CLICK ON RELICS, DON'T BE PUT OFF BY THE WORD RELICS.

If your stitches do not look good on the top side you have a problem with the bottom thread. make sure you have the correct bottom tension: Is the thread under the bobbin tension plate and when you hold the bobbin and case lightly in your hand the tension should be set in a way that there is little resistance , yet still some, when you pull the thread. After you set your bobbin tension, you may have to adjust your top tension to balance. Also make sure the thread comes off of your bobbin the way your manual tells you, clock or counter clock wise.
Make sure your bobbin (plastic) is not sooooo old, buy a new one.

You can find your manual @ the Necchi distributer (it is a copy of your original) @ 1-800-525-9987. Mine cost $14.25- Shipping & Handling, included. Also, they let yu download or get a copy of your manual (or sent on a CD), if it is listed where the Necchi's are listed ( in order of first letter of your brand). I ordered mine from the distributer.

Sheila,
I called the company which sells Necchi Machines and parts(Allyn)
in the States about the belts.Their Number is 800-525-9987. The parts department says Necchi used several different motors with differing motor mounts which means there is no standard motor belt for this model machine. The only way to get the right belt is to either take in the machine or the old belt to your repairman. More than likely he will have a Generic belt which will work.
sewman7