Hand-crank a Yanmar ... Yeah, right!!
The next person to start a Yanmar 3GM30 on a hand crank will be the very first and if someone says they've done it, plug him onto a lie detector because I don't believe it. And if they pass the lie-detector test, test his compression next, the engine's probably knackered.
I tried on mine using every known trick (other than connecting it to my main sheet!!) and never even got close. The broken wrist is about right.
And this is a little engine.