I agree with Wendy. I think that the top thread did not actually sit in between the upper thread tension discs. Make sure that the presser foot is UP when you thread your machine.
Originally Posted by azwendyg
It looks to me like your top thread may not be actually in the tension disks, or your bobbin tension is way too high. If it was just a speed issue, those eyelashes would be more prevalent around the curves, but yours look fairly consistent throughout.
First, I'd take the thread out of both the top and the bobbin and totally re-thread.
Next I would do a "regular" straight stitch on a practice sample using a regular foot with the feed dogs up and stitch length set "normally" to see if the tension looks good that way. If not good, adjust and necessary and re-test. The tension shouldn't need to be changed significantly between doing a regular stitch and a FMQing stitch as long as you are using the same threads as you will for FMQing.
Then I'd drop the feed dogs,
Set the stitch length to zero,
Put on my quilting foot,
and do some test meandering on a practice sample with the same or similar backing batting and top fabrics.
When all looks good on the practice piece, you'll be all set to go back to your quilt!
This is the process I go throught each and every time I set up for FMQing a piece.