My Janome machine won't take either YLI machine quilting thread or Superior King Tut - they're too thick and jam in the tension discs (and believe me, I've tried every possible tension setting). I assumed that it must be a quirk of that machine, as if they're sold as machine quilting threads, they should work on a machine - right?! I've just bought a Singer 201, specifically for FMQ because of the problems with the Janome, and am very surprised and disappointed to find that I've got exactly the same issue. Do other people have this problem or have I just been very unlucky?

Sorry you are having problems with those threads. I haven't tried machine quilting thread, I use the cotton Essentials Thread from Connecting Threads and my machine loves it. Maybe you should just switch to a regular cotton thread.

I'm just reluctant to admit defeat! If they say they're machine quilting threads, an obstinate bit of me insists that they should work on my machines - or at least on one of them!

check out this video about machine threads...... http://www.thequiltshow.com/os/blog.php/blog_id/4268 then check your thread to see if it has "memory". If so, then it's probably a waxed or coated thread.

I have used the King Tut with no problem in my Brother and Janome. I hope you get the problem sorted as it must be frustrating :(

I have a temperamental Bernina Love King Tut but took some trial and error to get it working Have found I have to use correct needle to thread

I do not know what model Janome you have but I have this for mine.

http://www.amazon.com/Janome-Tension.../dp/B002F01SY0

It is suppose to help with the issues of FMQ on it. While I have not yet had the opportunity to use it, it does get rave reviews in the Yahoo group. I hope you resolve your issue soon!!!!

I can't even get as far as thinking about needles, as it won't go through the tension discs! It seems weird that I should have the same problem on 2 such different machines -simple 1950 vintage workhorse and 8 year old mid-range Janome - so I'm curious to know if this is a common problem with these threads or I've just been very unlucky. I'd love to be able to use King Tut - wonderful colours, and Superior is my favourite brand.

i also use king tut on my janome 11000 with no problem and love it
good luck
Gale

Take one of your machines and the thread to your nearest machine dealer. Since it's happening on such different machines it's more likely something you're doing or not doing right.