Re: First build done but have a question!
Okay, the CNS:
The screw by the air cleaner is the idle air screw. When the engine is idling, it's only pulling fuel through tue pilot jet, and that screw adjusts how much air goes through the pilot circuit. This *only* affects fuel mix at idle, not high in the throttle range.
The other screw is the idle speed screw. In for higher idle, out for lower idle.
I've heard that these screws on the carbs that come with the 2010 Grubee kits are Loctited in place. Careful not to strip them, they're kind of soft.
The other adjustments are just like in the NT: move the needle clip around, rejet the main jet (I'm not sure what the stock size is). I've also heard that putting the throttle needle from the NT carb in the CNS might help with throttle response, because it has a different taper.
But your problem is with idling. You don't mention what fuel mix you're using. 24:1 for break-in, and 32:1 after that, unless you're going to use synthetic, in which case you'll need to follow the guidelines from the oil manufacturer. Many of the instructions say 16:1, which is just plain wrong, and could cause the condition you describe.