I have a viking sapphire 850 and having alot of trouble adjusting the tension. (My husband wondered if I was yelling at to cause "Tension") thanks dear. anyway I have rethreaded, changed needles and using bobbin that came with machine.
Any suggestions, also can't find instruction book. :oops:

Are you threading the machine with the presser foot in the up position? The up position releases the tention on the tensioning disks. And are you sewing with the presser foot down? Also, important for the same reason.

have you contacted your dealer

I have the Viking Sapphire 875Q. I had the same problem once and couldn't figure it out. A friend suggested that I change over to a new spool of thread and this solved the problem for me. I was told sometimes the thread can be "defective". Hope you can get back up and running soon!

hmmmm I think I'm threading in the "Up" position but will make sure. I have changed spools. It's all from the same company tho, but never had the problem before. Guess it's just getting an attitude !!!!!!!!!!!!!!!1

Without knowing what you're doing, it's hard to troubleshoot, so these are general suggestions.

Try putting your thread on a separate thread stand. Or, if it's upright now, put it in the horizontal position.

When you thread the 850, make sure the presser foot is in the highest position - there are two stages. When you thread the bobbin, make sure you hear a little click when you pull the thread through the bobbin tension area.

And...your needle should be the appropriate size for the thread you are using.

hi I have a sapphire and I have to put the tension up to 9 just for piecing and I still get little dots on back and it makes waves on my edge of the square keep changeing it to fix called the store they say this is normal I thought that good tension is when one color on top one on bottom should not show up on eather side like my old 301. any help out there that has same machine tried all kinds of thread brands and needle mine is a 850 thanks