I'd agree about taking out the plugs and cleaning them off, also if it might not start immediatly but if you let it sit overnight it may... there should be drains on the float bowls of the carburators, i'd loosen those bolts and drain out any excess fuel in the carbs, could also have gotten engine oil in the airbox/carbs/plugs... or the tip over switch could be still be engaged if it didn't return to its upright position