Charlee, I love you! You are always so helpful. I sewed it for a few more minutes after you posted, and the smoke started clearing in about a minute. It got less and less, and then just stopped. So that issue is gone.
But, now that I have had a chance to play with it more, I have discovered other problems. She skips stitches and does not sew the special stitches. Straight stitch does the best, with only a skipped stitch in maybe 25 stitches. Zig zag is awful with skips, and the decorative stitches just appear as zig zag.
Another thing, which I have never seen before with any machine, is the needle thread is continuously stripped. By that I mean that I will notice the thread going through the needle hole suddenly appears as a tiny thread, and further up the thread there will be thread bunched up. I hope I am explaining this right, I don't have the manual with me right now to say the official name of things.
I tried changing the needle, the thread, the fabric, the tension, and still the same problems. I also took out the bobbin holder (case?) and cleaned under it. I am confident that I replaced it correctly, but maybe I am wrong.
I had cleaned the cam stack and removed a bunch of crud, and also taken apart the tension unit before I discovered all these problems. I did notice on the tension unit that the little round circle with the finger thing sticking out was turned so that the finger was pointing towards the machine. In the 301 I have it points away from the machine, so I assumed it was on there wrong and turned it when I replaced it. Was I wrong?
I resisted having this machine serviced by a professional, but now I wonder if I am over my head with this. I want to learn how to fix my own machines, but I guess I need help and guidance right now
My grandmother was a meticulous person in every way, so I know this machine was not abused. It was a one owner machine.