I just got a new to me Ultimate 2 about 2 months ago. I LOVE IT!!!
However, I bought it from a lady in her mid 70's who liked to quilt with fishline. YUCK. I couldn't get the machine to do diddly squat. That is why I am married to an Engineer! My hubby looked up all the info online, cleaned up the burrs in the bobbin, retimed it several times, and took apart the tension assembly and put it back together the RIGHT way (it had been wrong) and now it quilts like a dream.
I had a mid arm for 5 or 6 years, so that helped me learn about troubleshooting with tension and thread issues.