Originally Posted by MollieSue
Thank you, Linda!
So for the top tension, you tighten the little screw in the bobbin (I've never messed with that before)? Not the regular tension thingy, on the front of the machine?
The bobbin thread isn't a loose loopy, more like just lying there, not being pulled down snug....
No. The screw in the bobbin is to loosen or tighten the bobbin thread. The top tension knob is usually on the front of the machine. If it's on 5.5, try moving it to 8 or 9 and see if that improves the stitch. It sounds as if the top thread is not pulling hard enough on the bobbin thread.
Sometimes the discs in the upper tension get clogged up so the correct tension isn't delivered to the thread. Do you see where the discs are? The thread passes between them, probably behind the knob. You can use *unwaxed* dental floss to clean between the discs (with thread removed, of course). Sometimes there is a tiny piece of lint or thread caught in there.
Also, you might want to change the needle if you haven't done that, and check underneath the feed dogs for built-up lint that needs to be removed.
Do not fool with the bobbin screw unless you read up on what you are doing. Changing the tension knob setting on top won't hurt anything, but you can really mess up the bobbin screw if you don't know what you are doing.