Mack : Good way to get yourself hurt bad. Broken thumb, torn shoulder broken arm. You never grab the crank with your thumb wrapped around the handle, and you never full circle crank an engine like that.
You prime it, bring it up on compression, turn on the spark, mag etc, and lock crank at bottom of rotation, grab without your thumb around the crank and flip the crank upward so if it fires early it just snaps the crank out of your open hand because if that thing fires when you are on the downstroke you can kiss that shoulder and arm bye bye. Take it from someone who works on this stuff every day. I'm not being a troll, or a know it all, but I have been doing this a long time and I've seen a lot of guys hurt bad.