I have a brother cs6000i and have been FMQ on a very large quilt without issues. I changed the top thread to a different color and now the tension is all messed up....eyelashing and most of the bottom thread is just laying on the surface. I've tried adjusting the tension to accomodate a different thread, but no luck. I know the tension needs adjustment but after poring over the owners manual, I still can't decide how to adjust. Does the adjustment dial with numbers from 1-9 adjust the tension on the top thread or the bottom? Does the tension increase with a higher number? I am so confused right now and really don't want to rip out any more bad areas. HELP!!!

I remember the saying right tight , left loose. That's. All I canhelp with. Tension issues scare me!!!

maybe practice on a test sandwich until you get it right before doing it on your quilt, that way you can work out all of the bugs. Also try rethreading the entire machine, maybe the machine was threaded incorrectly. Also did you make sure your presser foot was down when you started, sometimes its hard to tell on the darning feet. Also I can't remember if the foot has to be up or down when you thread the machine, but I think someone on the board with more experience can help you with that

have you checked to see that the thread is properly in the tension disks? and that the disks don't have lint clogging them??

On most machines the dial on the top of the machine adjusts the top thread tension. The bottom thread (bobbin) is adjusted with a small screw on the bobbin case. Also you can use dental floss to clean out the tension disks.

What happens when you switch back to the thread you were using without any trouble?

Is the new thread significantly different in size from the one that was giving you no trouble? If so, you will probably need to change the needle size.

Did you change the bobbin thread? Is it significantly different in size from the thread you were using without any trouble? If so, you will need to adjust the bobbin tension first, then adjust the needle thread tension to balance with the bobbin thread tension.

I'll check back after a while and see if you need any help. :)

The dial will adjust the top tension. As Kat said, the bottom tension is adjusted on the bobbin case.

Before you tried adjusting the tension, did you check two things?

1. Presser foot down?
2. Did you pull the bobbin thread to the top of the quilt?

Those two are the ones that get me EVERY time! ;) Less common for me to get caught on is that the machine needs to be rethreaded...

The presser foot was down for sure?

Make sure that the thread went properly in between tension disc, bobbin is clean & lint free especially in the bobbin case area where you thread missed the tensioner might need adjustment on tension. Have yourself a Sanwich practice piece before you commit to quilting.
If everything else failed, rethread both top & bottom & playing along both top & bottom starting with loosey to gradual tighty.

presser foot was down, machine won't sew with it up....bobbin thread the same throughout entire quilt and cleaned bobbin case too, just in case that was the problem.....went from a poly thread to a cotton on the top