It seems every sewing machine is different in it's likes and dislikes for mono thread. I have the problem on two different brands of machines. After adjusting and readjusting I have decided I need to go for professional help and will consult the sewing machine dealer. I would suggest the same for you if your dealer is availabe. If not, then email the machine manufacturer and ask the question. There is good info on superior threads web site and am sure the other thread manufacturers have the same kind of info. We all have different problems with mono thread and it is better for you to go to your machine manufacturer for advice.