I think, you gotta let the engine break in for a couple of tanks before starting with the tweaking of it. As long as nothing is horrifically wrong with the motor (like a leaky head gasket or bad assembly woes), it'll run better and better as you ride it. I had the 66cc $100 no-name kit, and once I got the head issue sorted out, I was able to pull the 36T no problem. (I ended up running the 36t so that it was vibration-free at about 25 mph).
I'm not going to take credit for the analogy, but these little 2-strokes are like adopting a baby or a puppy- get to KNOW them, and find out what works first before going in and changing things.