I assume you mean at the Handlebar, and not down at the engine area......there are two ways to adjust the cable slack. I don't see one on the parts microfiche at the handlebar level.......for the NT nor NC......my 2012 NC does not have one (but wish it did now). But someone else needs to double-check me.
This item might be something we can "retro-fit" from another Honda model......maybe a dual purpose model??