Maybe you need to reduce tension also?
FYI C&C normal 'dual duty' is 50WT. The 'Fine' is 60 weight and comes on a lavender spool. It is not as perfectly smooth a thread as Superior when you look at it magnified, but it is certainly usable. The Light looks and feels a lot like the 60WT Presencia cotton in my humble OTT-magnified and lit opinion.
I have been thread shopping!!! can you tell?