on my kenmore sewing machine , when i FMQ, i put my pressure adjuster on O and my thread tension on 4, the other day i was FMQ on a thick quilt and had to have it down around a 3 i was using a differant color in the bobbin than the top thread so was having a problem with the bobbin coming up on the top of my quilt
i hope this works for you , kinda practice till you find the right number