Originally Posted by irishrose

That's the Elna, right? What kind of needle are you using and what kind of thread. Miss Elna is a bit fussy about such things. She likes Schmertz needles and the old C & C thread or Guterman - no inexpensive polyester. Take a small brush and clean out the bobbin area well - you can use a screwdriver and take it apart, too. A thread caught under that black hook deal will cause havoc. Because the Elna, like the Necchi, is engineered to high specs there is little tolerance for 'foreign' objects.
edit: In reference to the previous post, the needle threads from front to back on mine which is only a little newer than yours.