I would pull the plugs like somebody else mentioned. It is hard to know how much oil got into the cylinders. If the valves in one of them were closed the oil would have nowhere to go and could cause the problem. Pulling the plugs will eliminate that possiblity or clear it and you will know for sure.So this is a simple fouled plug thing, and not a over compression thing due to the volume of oil in the cylinder?
I guess what I’m trying to figure out is why the motor only half cranks?