Right needle hits stitch finger "A" and breaks or bends, leaving nicks in the stitch finger. I don't know what stitch width to use with each finger (A and B), or if it makes a difference. Manual does not explain. Someone please help. Thanks.

Interesting. I looked through the manual and didn't find anything about the twin needle selector. You might try it anyway. Just set the needle to the center position and the stitch width to zero. Leaving it this way should prevent the needle from hitting anything and breaking. Otherwise, contact Singer support.

These are suggestions to try. Clean the lint, dust, thread pieces from the bobbin area, the feed dogs, and under the needle plate. Oil the machine according to the manual--use only fresh, good quality sewing machine oil.

First, make sure to install a brand new needle and verify that it is installed facing the correct direction. Confirm that the needle you are using is compatible with the thread and fabric of your project. Spend a couple extra dollars for good quality needles. You don't have to buy Schmetz, as there many other good needles on the market. Avoid the generic or cheaper brands.
All About Needles (see the troubleshooting guide especially)

Check that the thread is not too large for the needle's eye. If the thread is shredding and eventually breaking, it could be old or poor quality thread or the needle is shredding the thread. Some needles have a larger groove (scarf) on the back above the eye that protects the thread as it pierces the fabric over and over. Sometimes, coarse fabric will tend to shred the thread because it acts much like sandpaper.

Try a different brand of thread--preferably a good quality brand of thread. Avoid using old or bargain bin thread. Some machines can be very finicky so some experimentation may be needed to determine the brand of thread that works best.

When threading the machine, ALWAYS RAISE the presser foot throughout the process so the thread will seat properly in the tension disk. Confirm with the owner's threading instructions that the thread follows the correct path and does not skip any guides or wraps around something. Also check that the thread spool does not have any nicks or burrs that may be snagging the thread as it unwinds. May seem trivial, but confirm the thread spool is unwinding in the correct direction on the spool pin. Thread is twisted when it is made. If it comes off the spool in the wrong direction, it will reverse the twisting, making it loop, knot, and weaken as the fibers untwist.

When sewing zig-zag, generally the tension needs to be loosened more than straight-stitch, otherwise it can cause the fabric to create a "tunnel" between the zig & zag stitches. If the fabric tunnels, the tension is too tight. The tension is correct when both the upper and bobbin threads meet in the middle of the fabric. It doesn't matter if your tension is set @ 5 or 2 as long as the upper & bobbin threads meet where they should. The upper tension setting is not static. It is meant to be adjusted, probably every time you change needle, thread, or fabric. Always test the tension on a piece of scrap fabric from your project. Duplicate the situation you plan to sew, ie use the same needle, thread, fabric, the number of layers of fabric, stabilizers, etc. on your test. Then when you sew your project, you will know that it is set correctly.

http://www.craftsy.com/blog/2015/03/how-to-adjust-sewing-machine-tension/

One last thing to check--look for any nicks or burrs in the bobbin area, ie the hook, the needle plate. Frequently, when a needle breaks, it will create a notch or nick where it has hit the hook or plate. That nick will tend to catch thread and cause it to break or stitch improperly. You can wrap your finger in a piece of hosiery or other fine fabric and run your finger around the metal parts to see if it snags anywhere. If it does, sometimes if the nick is small it can be smoothed with a fine emery board or sandpaper. However, if the nick is large, you will most likely need to replace the part or take the machine to a technician.

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You need a repair shop - sounds like a part is worn out.

Your model doesn't have a specific needle position adjustment. But you could try this - set it to the shell stitch or lingerie stitch on the stitch selector but leave the stitch width setting on zero, this may move the needle to the left most position with any luck.

Other possibility is to put it in a step of the buttonhole sequence, but again leave stitch width on zero and see if this moves the needle bar to the right or left for you.

You must remove the pins as you sew otherwise you will either break the needle or do worse damage to the machine. Home sewing machines were never meant to sew through metal.

Hello,
Here are several things to try.

* When you insert your new needle, make sure it’s positioned correctly (usually with the flat side away from the bobbin, but consult your manual), that it goes all the way into the holder, and that the screw is securely tightened.


If there doesn’t seem to be a problem with your needle, try the following:

* Check your pressure foot and make sure it’s attached securely.


* Change your pressure foot Your pressure foot may be bent, causing your needle to hit it.


* Don’t sew over pins a needle that hits a pin can break. Always remove the pins from your fabric before they reach your needle.


* Don’t pull your fabric as you sew. You could be bending your needle back, causing it to hit your needle plate instead of going into the hole. Just guide your fabric, letting it feed on its own.


* Check your needle plate and make sure it's securely in position.


* Change your needle plate. If you’ve been using a straight stitch needle plate (a plate with a small hole, often used for sewing fine, delicate fabrics), switch to a needle plate with a wider hole.


* Check the position of your needle. Sewing machines with zigzag capability allow you to adjust the position of your needle – right, left, or center. If your needle is not positioned correctly, it may be hitting your needle plate or pressure foot.


* Un-thread your machine and remove your bobbin. Clean any loose thread or lint out of your
bobbin case. Re-thread your machine, reinsert and re-thread your bobbin.

* Change your bobbin. There could be a nick along the edge of your bobbin spool that’s catching your thread as you sew.

Also, before you start to sew a seam, hold the upper and bobbin thread tails. Hold them back
and out of the way as you sew your first couple of stitches. This will keep them from getting
caught in your machine.

I hope these solutions help you.

If your needle is hittle the face plate, then it is out of time.. I would take it to your local repair center.

your machine probably needs to be retimed.

You need to use the zig zag or satin stitch presser foot with the twin needle. You also need to make sure you have the zig zag plate on your machine. Also, remember when using the twin needle, you cannot put your stitch width beyond half way. The best thing to do is once you select the width, turn the handwheel to see where the needle is going to hit, you want to make sure it clears the plate or it will break.

If it was sewing correctly BEFORE the needle break...why did the needle break in the first place?...and what fixes did you make?
If it sewed properly...what changed?

Cut your upper thread close to the spool...make sure the presser foot is raised and pull the cut off thread section through/out of the machine from the needle area (sewing direction...do not pull the thread backwards!)

Clean out the bobbin area...remove any traces of lint or pieces of thread...look for any broken off needle pieces... brush the bobbin area out....then add a drop of sewing machine oil (but only if your manual says to oil that area).

Remove the needle plate to expose the feed dogs...brush/clean out that area too and add a drop of sewing machine oil...then secure the needle plate back on.
Replace the needle...do it again...yup...some needles arrive bad from the factory. Make sure the needle is inserted and positioned properly. Then thread the machine WITH the presser foot in raised position. (The thread needs to get seated into the upper tensions.)
..with the.presser foot down...thread the new needle.
Oh...and use the correct needle for the thread. (a universal 80/12 is standard).
Thread can cause issues too. Try a different bobbin, or maybe a different spool of thread to see if that makes a difference.