My favorite thread is Mettler or Gutermann, but do you use the large spools on your Juki? Don't ever use the 2 for a dollar spools, I don't know all the brands on large spools, I don't have a "quilter". I also use essential threads from Connecting threads. Some people like the Coats and Clarks, but I have sometime had issues with that thread. I use YLI quilting thread and have gotten some nice stuff at quilt shops. I'm at home so I can't check my threads. Also is your thread old? Hope someone else can give you more help!!