When you say bobbin stitches are loose, do you mean the bobbin thread is just laying on the fabric? If so, it's not your bobbin tension that's off, it's your top tension. Sounds to me like it needs to be higher. If it looks bad on the back, the top tension is off, if it looks bad on the front the bobbin tension is off.
Also are all the stitches bad or just on the loops. If all are bad, it's a tension issue if it's just on the loops you are going too fast around the curves.
Last edited by PaperPrincess; 10-03-2012 at 05:09 AM.