Have you tried the blue dot bobbin case? I have a Janome 8200 which is very similar to your 7700 and picked up for about $30 the blue dot case and it makes a difference for me. I also have better luck using 100% polyester thread - Gutermann works well for me. I have some Isacord that I just recently purchased but will need to get a thread stand to use it. I have had good luck doing FMQ with Aurifil as well.

I don't do a lot of FMQ, partly because I'm not very proficient yet, but also because I really like straight line quilting.

Check out Leah Day's website too, she FMQ's (or did for a long time, I think she's back to a Juki now) on a 7700.

Terri