I know this should be under Vintage Machines but it's not a choice so hopefully it will eventually find its way there.
I recently bought a 99K and love it, but when I sew on it, it pulls the bottom fabric up ever so slightly into the stitching. I have tried adjusting the tension but that doesn't seem to be the problem. Does anyone have any other suggestions? It runs beautifully otherwise and I really don't want to have it serviced right now unless absolutely necessary. Thanks.