put your machine in neutral...that point in the lever arm where the thread flows freely... now hold the two threads together and pull out about 12 inches and then release the tension but do not let go of the threads. when relaxed, you will see if the threads are even in tension, the top is shorter or the bottom is shorter... if your bottom thread is longer, which sounds likely, take the bobbin case out of the machine...hold the bobbin by it's thread only and see how quickly the bobbin case (with bobbin inside) falls downward... it should slowly move downward without you doing anything, no shaking or prompting. if it falls freely and fast, (also likely) then you need to tighten the tiny screw right at the base of the hook that sticks out on the bobbin case. i never do more than a 1/4 turn, even if it is just completely loose. tiny adjustments on bobbin case, always. now sew again and keep trying to get top and bottom balanced... If the bobbin moves smoothly and slowly downward, then adjust your top tension to a lower number... test frequently with the test on the top line...
ps...please make sure your bobbin is threaded properly before making any adjustments, don't rely on memory, get your book out, some go left, some go right...you must check this one time since your attempts were not helping.
Last edited by deemail; 11-08-2011 at 11:19 PM.