i know to some this is a silly question but new to me it is.
Mr. Ironman: I would recommend that you get a hold of a junked engine, running or not, and just tear into it to see how and why things work the way they do.
You are obviously curious about this stuff (hence the 'silly' questions) so why not give it a stab.
If it's a junk engine it won't matter if you

it up

. I think you would be surprised at how simple and basic these things really are. If you get stuck we will help you get through it.
I usually cruise the neighborhood when folks do their spring cleaning and can find old lawnmowers, edgers, tillers, snowblowers/throwers etc. out at the curb. Most of them still run while others may require some tinkering (fouled plugs, shorted ground wires, bad coils, dirty points) to get them going.
I put up signs around my work place listing engines I am looking for.
So far I got a 2hp Briggs edger, 6hp Briggs Quantum, 7 hp Briggs snowblower, 5hp Tecumseh snowblower and 3.5 Tecumseh mower. A 750cc Honda motorcycle

on the way.
ALL FREE. Most people are just glad to rid of this stuff.
Nothing ventured, nothing gained.
Sorry about the

fftopic: post.