I don't know for 4 stroke augers but if you lay a four stroke outboard down wrong oil floods the fuel system. I believe it's called hydrolock. You can pull your heart out and it won't start until the oil clears. Since LP runs through the fuel system as a gas there's nothing to rinse the oil out so it's even more difficult. Best bet is pull the carb and rinse it in straight gas to try to clear the oil and it's still a lot of work. Load the combustion chamber with starting fluid when you try to start to get the remaining oil sucked through the system. Not a mechanic here but I know how things work and you've got a job on your hands. Perhaps there's a real wrench here with better advice.
EDIT: Might also be worthwhile rinsing the combustion chamber out with gas as well. Pull the plug, make sure the plug wire if completely insulated from contacting the engine, pour the cylinder maybe a quarter to a third full and gently cycle it and pour it out. Might even have to repeat that.
Good luck!