Hi I have the same machine. I can’t seem to thread my machine and keep it threaded. Do you have any tips? I have both of the manuals on how to thread it but I have not been successful with it.
try with your tensions first. after that, look for burrs, both on the needles and the loopers as well as the throat plate. I just worked on one a little while ago and I loosened the tensions too much and the thread started acting up. Start simple and then start looking at other things. Timing etc.......