Are 319K's picky about thread?
I was setting up my wife's 319K to do some patterns on my quilt blocks. I had fits getting the tension right.
The thread kept slipping out from under the little tension spring on the bobbin, then the top wouldn't cooperate either. The thread kept popping out of the top thread guide and breaking.
I kept at it and ended up changing threads, going to heavier thread, and then had to loosen the bobbin tension almost a full turn of the screw.
That seems to have helped a lot. Now I need to go back to the bright yellow and gold thread and hope my adjustments will work with that as well.
Is your 319s thread picky?
Joe