Expert advice that worked for me:
Superior Threads GUARANTEES our metallic threads will work in your machine. Follow these two simple guidelines:
1. Use a Superior Topstitch #90/14 needle with metallic thread.
2. Adjust the top tension all the way down to a "1."
See video about using metallic thread in your sewing machine, no matter which brand.
http://www.superiorthreads.com/videos/chapter1/
http://www.superiorthreads.com/videos/chapter1/