What zero turn? What engine? My ESP has been down due to the heat and humidity and the government has shut down access to the spy satalittes because of the recent wire tapping scandal. If you would please post the units model and serial numbers as well as the engine model and serial numbers and we might be able to help you. Without them I would guess that there is no seal on the governor shaft and you have a blown head gasket, creating a preside build up of pressure in the crankcase.