Does this machine have a computer? When I switched from my Viking Emerald 183 to the Viking Opal 670, I had a hard time getting the tension adjusted correctly. Since the tension is pretty much set by the computer, one has to make the correct fabric choices. I discovered the FMQ works better on "woven medium" rather than "woven heavy". I have my tension set on ~4.8. I use a Top Stitch 90-14 needle. What kind of thread are you using? I like King Tut by Superior. A 40 wt. thread works better for FMQ, in my opinion. Hope you get it figured out soon. JCY