I can think of only one more to add to this: be sure that the needle isn't in backwards.

I have a 6600 and had to slow down! Both myself and the machine, and I found I cannot use the same type of thread in the bobbin that I use on top...

First I hear of it; what makes it different?

If you've tried everything perhaps it needs to go to the shop. I once had a thread breakage problem and he found that there was a "ding" on one of the parts under there somewhere. He said I had probably hit a pin going over it. Don't know, but he changed the part and my Janome has been singing ever since. I don't have the 6600 but I have the MC4000.

Slow down a little and see if that helps. How old is your machine? I have one and some days, it doesn't like anything; other days, it'd use rope if I could find a big enough needle. Mine is not a year old yet...and I don't FMQ on it because I have a long arm. But, from past experience, I'd say your speed has as much to do with the success as anything...good luck!

Is the thread breaking from the top thread path or from the bottom? If it is breaking from the top, thread your machine to the last thread guide, by passing the needle. Leave a fairly long tail of thread at the last thread guide. Pull an additional foot or so of thread off the spool then cut it, holding on to the end. Take the other thread end at the thread guide in your other hand and gently move the thread through the machine, see if you feel it catch anywhere. You might have to pull the thread back and forth a time or two until you feel where it is catching.

If it is breaking from the bottom the first thing I would check is to see if your thread cutter is clogged with a stray piece of thread or fuzz. If your bobbin case is clean, and the thread cutter is OK then try another bobbin. Also check your stitch plate - they can crack at the feed dog slots and you won't see it, but believe me, a crack in the stitch plate will cause all manner of trouble. An 75/11 needle is still pretty small, can you bump it up to a 90/14 to see how it does?

I use Connecting Threads thread in my 6600, with no problem. I do have the special bobbin case, and it is well worth every penny. I got it from the dealer. In addition to what others have mentioned, I set the machine to Mode 2 - Pattern 11, set the foot pressure to "1", and set the speed to medium. I also use a Supreme Slider and gloves. I agree that you may be going too fast if the thread is breaking. Good luck and I hope you are able to resolve the issues. The 6600 is a wonderful machine.

I am sorry about the loss of your son. My heart goes out to you. I lost my son 6 years ago, and miss him everyday.

I only use topstitch needles. Has a longer hole so the thread slides through easily

Thanks Wanda, only someone who has lost a child can know how it feels. I am sorry for your loss. Most of the advice
given here is moving too fast, so I am going to slow down. It seems to go okay for a while and then the thread breaks.
So you all might be right.
Thanks to all for their suggestions. You all are the best.

Mary

My husband just bought it for me in Feb. for my birthday.

Hi, I have had this machine for 9 years, you will not be disappointed with it as its Janomes work horse machine. First of all take out all the tread and re thread, if no joy with that change the needle, this machine really likes its own needles I found that out the hard way. Also if you ever have trouble with the feed dogs not working, just use the handwheel turn it back and forth, it will start to work again. I put mine in for repair thinking it was damaged two years ago only to find the man said it was fin, that got me thinking it must of me, it also happen this week but new how to fix the problem. This is a good machine stick with it as there is a leaning curb with any manchine. Ps sorry to hear about your son, my thoughts are with you x
Gwen

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