Originally Posted by
HouseDragon
Completely opposite to an earlier post, my Viking 875Q sews perfectly no matter what thread I buy. I have tons of colours of Connecting Threads Essentials and King Tut and Rainbows plus others. But no C&C because my previous machine ~ 1965 Elna Supermatic~ didn't like it. I also occasionally use Bottom Line in the bobbin.
I always clean the bobbin area when the bobbin needs rewinding. I think that makes a difference. If you don't care enough to keep your machine (any kind) clean, you can expect to have problems!
I highly recommend Husqvarna-Viking machines. 
The only thread I've had problems with in a vintage machine is the 2 ply Masterpiece thread, the top thread breaks constantly. My newer Viking and old Berninas don't do that; the featherweights and all the others don't like it.
I have an 875Q also! We're currently using King Tut(932 Cairo) to quilt a twin size quilt, it looks wonderful. I'm using a turquoise 50wt. Gutermann in the bobbin, 90/14 top stitch needle. I clean out the bobbin area after every other bobbin change.
Sharon