Originally Posted by tjradj

I did my first fix! No, not drugs, sewing machine.
Yesterday at quilt club, one fine lady had her white 221K featherweight there. She and another lady played with it for 2 hours trying to get it to sew. So, 15 min before quitting time, I had to take a look.
I got the bobbin out easily - after reading online (ahem)
Found the undercarriage FULL of thread.
Got that all cleaned out.
No go. Everytime you started her up, she'd fill the bobbin case with thread again and quit.
We oiled, and we oiled, and we oiled some more.
But still no go.
So, in a moment of bravery (or insanity), I asked if I could take it home to look at it and see what I could do. And she agreed!!!!!!!!!!!
So home we went, and onto the kitchen table she landed.
I carefully took out screws, and taped them to a paper with a label as to where it goes.
I even took the bobbin case apart, and took the tension spring off and everything. Then I dropped one of those screws on the floor. A carpet floor. The screw that's about half the size of an ant. So, down on my knees I searched, and I found it!!!! That REALLY surprised me.
I reassembled the bobbin case and left the tension quite a bit looser than it was, just so that I could feel the pull but the bobbin didn't fall down when I held the thread.
Put it together again, and the same thing happened.
Then, I had a eureka moment. I had had the similar problem with my own Janome recently, and the problem was a burr on the bobbin case. So, I started looking for burrs. There were a few gouges on the hole in the needle plate. I didn't think they were big enough to be a problem, but I burnished them flat anyway.
That was it. That was the problem.
With a fiddle of the upper tension, she was away.
She sews a beautiful stitch. I filled up a whole 8x8 piece of double fabric with thread just waiting for the problem to happen again, but it didn't.
That little burr was enough to stop that machine from sewing.
So I called her mama, and she'll be going home soon as we can get together.
But not before I play with it just a little bit more......