A couple of nights ago I had thread breakage. Machine was clean I changed from a organ needle to a schmetz needle, oiled it and loosened top tension, rethreaded. Thread stopped breaking, not sure what made the difference. I could see some weak spots in the thread. I normally only use organ needles.

I'm especially interested in this discussion as I have this machine and have not had many thread breakage problems. I did have one incident where the machine was skipping stitches while I was FMQ but it turned out to be the material. I was using four different colors of batik in the project and every time I would get to the blue one my machine would start acting up. I found that if I adjusted the tension for the blue one I managed to get the project done. It looks like I need to put some Organ needles on my Christmas list just in case.

there are lots of good sources for Organ needles.
i just happen to get mine at ctsusa.com

I buy Organ needles on Amazon. I think it's roughly $11-12 for 100 of them. I love having so many, makes me not hesitate at all to toss a dull or suspicious needle! Organ is what came with both my Janome and my Brother machines.

Wow, I love this board! Any time I have a question or issue with my sewing, I can jump on here and somebody will most likely have already addressed it. I bought a Janome Horizon 8900 QCP earlier this year and I have been terribly frustrated by the thread breakage when doing FMQ. I am new to it, but the whole reason got this machine was for free motion quilting. I am going to give the Organ needles a try! ;-)