If your top thread is pulling right out that means your bobbin tension is too loose and/or your top is too tight. Make a practice sandwich and test. First I would loosen the top. If that doesn't solve it all the way tighten the bobbin a fraction of a turn at a time.
I often refer to this picture guide from superior to remember which tension problem means which needs adjusting.
http://www.superiorthreads.com/educa...ottom-tension/