First thing you need to do is track down where the oil is leaking from. Clean up all the oil, run it for 1 or 2 min, shut it down and look for oil. It may be something easy like the gasket on the oil filter, oil hoses, or the oil pressure switch. good luck
I agree. The fact that "there was oil all over" leads to the oil being pushed out under pressure.....oil filter gasket, oil press. sender, etc.
Clean everything up w/ brake clean spray while unit is off & cool, and then start it up manually with lid open & front cover off......should be fairly easy to locate where oil is spraying from.