Your fuel injected cars have a sensor in the exhaust. That sends a signal to the fuel injectors to either add more air or add more fuel. That keeps it running pretty much perfectly at all times that's the nice thing about fuel injection. The carburetor generally has a primary setting and a secondary setting. And there set. They can be set a little off and still run relatively well.
So the where the carburetor works is like your toilet. You know how that little float inside the back of the toilet goes down when you flush it and it pulls water in until the float goes all the way to the top. That's how your carburetor works. It has a float in it or a couple floats that keep the fuel to a certain level in the float bowls. Then as air is drawn through by the Pistons going down and drawing are it also draws a little amount of fuel through a jet. Know if you put a bigger jet in it will draw more fuel and make a richer mixture.. and the opposite is true with a smaller jet. The idea is to get the perfect setting for the car that you're putting it on. of course I'm saying it this way because you're asking for layman terms and I want you to have an idea of how things work...
If it runs too lean as in not enough fuel in too much air it can run very hot. kind of like a blowtorch when you turn on the gas it just has a flame but when you add oxygen it turns into something that can cut steel...
It sounds like you started here with just a little bit of a heat Spike from a new cam break in. Careful this form can take you into untold in uncharted territories and have you more confused then you need to be. Now I'm not doubting the guys that are saying your carburetor is backwards or something like that but it seems like he probably just put it back on the way it came off? Let's just tackle one thing at a time here..
