My 1st quilt machine was the beloved MegaQuilter on a Grace Pro frame 10'. Loved that machine as I don't recall ever having to adjust the tension on it. I'm surprised you're having issues with tension so maybe the previous owner knocked it out of sync and it needs to be re-timed. Never had to do that either so can't help you. I've moved on to a larger system but still have fond memories with the MegaQuilter. I added a robotic system called PCQ to mine but moved over to a retrofitted MQR when the PCQ caused too many problems. Still have the puck if you ever go that route. Being its only an9" throat, left few options of quilting large designs. But for the price you can't beat it. Think I also removed the feeddogs too. Might take it off the frame and see how it sews on a regular table. Might have better luck that way.