I prime four strokes for starting in one of two ways, by stopping up the exhaust to create tank pressure while cranking or sometimes I will use a long piece of fuel tubing and just blow air into the tank vent until the fuel reaches the carb, and it is very important to have the fuel line to the carb filled with fuel. Flip forward a few times to get the cylinder primed, light the glow plug, set the throttle to idle, and then flip the prop backwards as I mentioned before, and I have a running engine, usually on the first try.

Notice the emphasis on throttle position, it is that important.

I'm well aware that OS says to use an electric starter on all of their engines now. I think it is a CYA thing and who knows, they may have a financial stake in electric starter sales. In the older days, they detailed how to hand start engines.