Here it is again because you're too simple to grasp the implications:
"Remember that there are also a lot of inert contaminates in reversion too, and they amount to wasted mixture volume because they don't burn."
Larry Widmer.
If you can't grasp how the different elements like Carb, Intake port, and valve contribute to this then sorry I can't help you. Maybe start with what an inert contaminate is........
Here's a hint: What's all that black **** on the underside of the air cleaner lid and how dose it get there........