I have that same machine. It'll be happy with lots of different threads, provided you use the correct needle for the thread, and a good quality thread.
1st - change to a good quality needle, the best I've found are the Superior or Organ titanium topstitch needles. The topstitch has a larger eye, and a bigger groove that will allow the thread to flow through it better, with less shredding. Use this chart to figure out what needle to use:
For Size #70/10 - #100, 60 wt., & MonoPoly.For Size #80/12 - #50 (50 wt.) threads.For Size #90/14 - #40 (40 wt.) threads.For Size #100/16 - #30 (30 wt.) threads and thicker.
2nd - Use a good quality thread - I've used Aurifil, Superior and King Tut all with good results, and other good threads should work well also.
3rd - Double-check that your machine is threaded correctly, looking in the manual and threading exactly as shown. Any variation on the manual-recommended threading or thread feeding will cause mega-problems.
4th - reset and test your tension for every thread change and needle change. Very small changes in the tension wheel make for big differences in tension on this machine. Also, make sure to clean any lint from the tension wheel plates and needle area regularly.
5th - Clean and oil the machine with every bobbin change. This machine eats oil.
6th - Don't try to drive too fast. Set your machine speed down a bit and go slower until you get really practiced. If you do all of the above and are still breaking threads, you might be over-driving it.
Finally - don't get frustrated! When you dial it in it's a great machine!
