Not Threading The machine is threaded correctly however I don't get any stitches in the fabric.

SOURCE: Sewing machine problem

I just solved this problem with much persistence and a few possible causes. Mkae sure the thread is good quality and cant shred, at least until problem is fiwed. Unscrew plate behind bibbin and check if there is any caught thread, this happens after bottom thread has been looping. Remove any and replace, wind down the needle to check it goes in the centre of hole.
And probably the most important fix it; the tension;
Have your tension set to zero, thread the machine, and when the foot is DOWN, make sure it is very hard to pull the thread. It should be easy to pull the thread when the foot is UP. If the thread is easy both ways it has not caught correctly in the tension plates, thread it again (and again) until this happens. It shouldn't be possible to thread the machine without it going in the right place, but it is. And make sure when you rethread that the foot is UP until you thread the needle-
Another problem maker I also had to fix; ever so slightly bent needle.

SOURCE: My ls2125i won't stitch

Start slowly, make sure your thread trails are long enough, I had this problem a LOT when I first started using this machine. (mainly because it was my first machine!)

Fabric bulge- Don't try to push the fabric through the machine, let the feed dogs do it. Your job is to guide the fabric.

Thread jumps- Also, like Outdoorsman said, the tension is probably off. On this machine, the tension knob is easy to find. It's the small one with the numbers on it. "0 1 2 3 4-5-6 7 8 9" 4-5-6 are your optimal sewing tensions. I usually sew on 4 or 5, depending on my fabric and type of stitch.

No stitches- Your lower thread may not be being grabbed properly/bobbin case may be jumping out of position. Open the lower case and make sure your bobbin case is secure, and the thread is grabbed properly.

Hope this helps!

~iamtyping

SOURCE: stitching loose. won't thread the fabric

try to rethread the machine all the way back to the spool of thread and check the top and bottom tensions on scrap of same fabric

SOURCE: Shirring fabric?

When putting your shirring elastic on the bobbin, don't thread the elastic through the bobbin holder,adjust the stitch length longer,and loosen the tension, other wise if you want to put it through the bobbin holder you have to loosen the tension screw on the bobbin holder, and then you have to adjust it back for ordinary sewing,

SOURCE: The top stitch on my machine doesn't seem like it

Hi. I think I know what you mean--the top thread looks like it's just laying across the fabric, right? This is because either the top tension is too tight or the bobbin tension is too loose. (Either condition will look the same.) Try it with a different color thread in the bobbin, you can easily see the bobbin thread cross the top thread on top of your fabric. Here's what to do:

1. since you should hardly ever need to adjust the bobbin thread, we'll start with the top thread.
   
2. Make sure you thread the machine with the pressure foot UP (opens the tension disks) but adjust the tension with the pressure foot DOWN (closes them so they will adjust). Use a size 12 or 14 needle and good-quality thread (it does make a huge difference!)
   
3. With different color thread on top and in the bobbin, stitch an inch or so and check the stitch.
   
4. Slightly loosen the top tension (move the dial so the numbers go lower). Don't move it a lot, just a little bit.
   
5. Stitch again and check. Repeat this process, stitching, checking, and gradually adjusting the tension dial until you don't see any of the bobbin thread on the top (or very, very little) and don't see any of the top thread on the underside (or very, very little).
   
6. IF this doesn't get the balance adjusted, then you'll have to play with the bobbin tension. (But generally, once this is set, you shouldn't have to mess with it again.)
7. There is a tiny screw on the bobbin carrier that tightens or loosens a very small metal strip (where the thread exits the carrier). To tighten the bobbin tension, screw this just a tiny bit to the right. (Turn it to the right to loosen the screw, to the left to tighten it.) Again, just make a small adjustment each time and recheck your stitches.