Kerry Gunn

I was just reading the book for my Mom's machine. Perhaps your bobbin tension needs to be readjusted for the leather?

Needle may be bent, even slightly can affect it. Also if you hold tension on the top thread sometimes it will act that way too. Happened to me.

I know from my home machine... that if the bobbin is put in with the thread unspooling in the wrong direction... it will not pick up the bobbin thread. Check that first, then replace the needle even if it looks ok. And make sure you've properly threaded the machine with the thread in all of the tension features. Good luck