Is the needle inserted correctly? and are you threading the needle on the correct side - I know that this can make a difference with the thread breaking - also is the thread feeding smoothly from the spool or is it catching on something. About the tenion - put a light color thread on the top and use a dark thread in the bobbin- that way when you stitch you can see what thread is looping. Make sure you don't have dust bunnies hanging out in the bobbin. Your thread should pull "firmly" from the bobbin. Hold it in your hand (thumb and index finger) and pull the thread with the other hand - it should be taunt when you pull the thread......good luck and keep us posted