Originally Posted by Nougat
Okay, the CNS:
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.
I'm using Echo PowerblendX at 16:1 to break in a new 2010 66cc Skyhawk. Starts on the first pull, idles fine, runs fine.