FOR LYCOMING CARB ENGINES:
I've seen so many people pirme, try to start, and if it doesn't fire then start pumping like mad at the throttle, aircraft is reeking of fuel due to over priming and is now in real danger of a fire.
So here is my technique, as demonstrated by a mechanic and it has never let me down since.
COLD STARTING
Prime, Mixture RICH, throttle set 1/4 open and crank. If no joy them stop a mo. Mixture to ICO and close thr throtle. Crank, advance mixture to fully rich. She most often catrches here so swiftly advance the throttle to let her idle. If not, justtweak the throttle to squirt in a bit more fuel butr do not pump at it.
HOT STARTING
Mixture ICO, throttle closed, crank, advance micture to rich. She always catchs here, so just enough throttle to get her idling nicely.
And now for the after starts..........