My stitch regulator will not work. I have had it looked at 2x but still will not change from 2.5 higher or lower.

TIP: A general rule of thumb is that if the stitch looks bad on the top it is the bottom tension.
If the stitch looks bad on the bottom it is the upper tension. The upper and lower threads play
tug of war with each other.
Tension
You need correct tension on the top and bottom threads, but you must also have correct tension on
the quilt held between the rails. You should have a small amount of "sag" in your fabric. This allows
enough movement of your quilt layers for the needle to penetrate and make good stitches.
Before you start making adjustments to your machine ask yourself, "What changed?" If your machine
was stitching great and all of a sudden it has loopies on the back or puckers, "What changed?" Did
you just change the bobbin? Did you just lift the take up rail? Did you lower the take up rail after
finishing your last quilt? Did you recently change the needle? Did you just roll the quilt?
If the take up rail with the quilted portion of your quilt is too high, it will result in poor stitch quality. You
need a finger tip space between the quilt and the machine bed. Higher will result in poor stitch
quality, too low and the quilt will create a drag on your machine's movement.
Look at your bobbin, a sloppy wound bobbin will not create a good stitch. Make sure that the threads
on the bobbin are snug and evenly wound. Check to see if there is a piece of lint in the bobbin case

Remove plate over feed dog, femove bobbin and bobbin casing. My guess is that you have debris, lint or a piece of fabric stuck in the works

Make sure the feed dogs are in the UP position and that the presser foot is lowered. The stitch length needs to be at least at 1 or higher (preferable is 2) for the feed dogs to pull the fabric through the machine.

...

A BASTING STITCH IS ONLY A LONG STRAIGHT STITCH. THE NUMBER THAT IS LOWER IS A LONGER STITCH (FEWER STITCHES PER INCH). YOU WERE LIKELY MOVING YOUR NUMBER HIGHER. AFTER YOU GOT TO A CERTAIN NUMBER IT NO LONGER QUALIFIES AS A BASTING STITCH BUT A STRAIGHT STITCH. USE A LOWER NUMBER AND IT WILL LIKELY TO STOP THE BEEPING.

Find the tensions on your machine. Usually a screw below on the bobbin regulates the top stitches tension. Usually a numbered wheel on top--where the thread is around it--regulates the bottom stitches. YOU NEED TO ADJUST THE TOP WHEEL, test on scrap material, and if looser, you are in the right direction. If it is still a mess. turn the knob to a lower number.

FIRST... make sure you are threading the top thread correctly
Then... make sure your bobbin case is threaded correctly

This sounds backwards but this is how it is done. If the bottom of your stitching looks loose, you need to tighten the TOP thread tension. A setting of 5 is normal, but if the bottom stitching looks better at a higher or lower number... go with that.

One needle does sit slightly higher than the other. The stitches not catching sounds like a tension or threading problem.

try adjusting the top thread tension one number higher till the
stitch looks normal

The stitch length dial needs to be set to a lower number (number of stitches per inch) to give you longer stitches. The tensions do not regulate the stitch length, the feed dogs regulate the distance the material is advanced between stitches. Also, make sure the pressure foot is applying enough pressure to keep the material in firm enough contact with the feed dogs.
<Ray>

A. To correct loose stitches, try the following: (1) Balance the thread tension. If the stitches are loose on top of the fabric, decrease the tension to the next lower number. If they are loose on the underside set the tension to the next higher number. (2) Make sure the needle/upper thread follows the threading path. (3) Check to see that the bobbin case is threaded properly. (4) Use a different size needle. For fine fabrics, use a smaller needle (size 9, 11); medium-weight fabrics require a size 14 or 16. And use a size 18 or "Denim" needle for heavy corduroy or denim.