What kind of thread are you using? The needle size matters but so does the thread type. Also, sometimes when thread is miss behaving try taking the spool and sitting it in a cup behind the machine so that it comes off the spool differently. This does help sometimes. Leah Day puts all of her thread in a cup when FMQ because it acts better. Good luck. I agree with the others, you shouldn't have to mess with your tension. Have you checked out Leah Day's website; it's all about FMQ and has great free advice and tutes
By the way, are you also using the same thread in the top and bottom; this is also important.
Last edited by romanojg; 10-02-2012 at 03:30 AM.