Thanks for all the great responses. Here are some more details. I have a Husqvarna Viking 540 "Lilly". I am practicing on uncoated 3oz nylon from Joann's with Gutermann Heavy Duty thread.
"What size sewing needle are you using in your machine?"
I have tried 90/14 and 100/16 needles.
"It sounds like you are adjusting the thread tension on the top side. Are you adjusting the bobbin's thread tension also?"
I am adjusting the top side thread tension all the way to maximum versus a middle setting for lighter weight thread. I am NOT adjusting the bobbin tension. I have read the manual and looked at the bobbin compartment closely and there does not appear to be a bobbin tension setting. Note, the bobbins on this machine are simply a small spool, rather than a case.
"Standard home machines generally shouldn't use anything higher than a V-69 thread"
I believe the Gutermann Heavy Duty is a #30-#40 weight thread.
"Did your sewing machine come with a basting stitch bobbin case?"
I don't have a basting stitch case, but your comments make me wonder about methods to reduce bobbin tension. I will see if a local dealer can help on this.
