Singer Featherweight tension issue solved
I recently changed the bobbin in my Featherweight. I immediately had problems with the tension. I made numerous adjustments to both the top and the bobbin tension to no avail. Once I stitched a test seam, I examine the stitches. Then I tug on one of the thread tails. Regardless of how the stitches looked, when I tugged on the thread tail, the thread just pulled out of the fabric.
I took the bobbin case out of the machine and examined it and the bobbin. I noticed that the bobbin (which came with the machine when I purchased it) appeared to sit a tiny smidgen higher than the bobbin case. I replaced the bobbin with one I had bought from Sew Classic.
I started sewing and the tension was perfect. I have decided to throw away all of the 'old' bobbins that came with my machine - since they don't seem to fit quite right.