I have noticed a problem with my 301. I will be sewing along and suddenly my tension is bad. If I pull out the bobbin I see that the bobbin thread has come out of the tension spring in the bobbin case. This typically happens shortly after I have installed a newly filled bobbin in the bobbin case.
Could this mean that the bobbin is wound too full? If this is not a possible cause does anyone have any ideas?
I took the machine to the shop after I first got the machine because I had problems with the tension. The SMG said he rebuilt the upper tension. When I got it home the stitches 'looked' good but if you pulled on one of the threads it would just pull out. I started adjusting the bobbin tension until the stitches both 'looked' good AND wouldn't pull out.
Now if I can just get rid of this pesky problem. Any help would be appreciated.