I know you don't have access right now, but one other thought I had was is the needle in correctly? My friend, Karen could not figure out why her Singer was skipping stitches. She had the needle inserted improperly. The older singers used the rounded needles. They needed to be threaded from left to right. Thank god, they switched to newer types so the flat back of the needle left for no mistakes. But still, the older types still require the rounded types.