Hi, I have a 1994 258 Vista with a 351 OMC, I/O Cobra outdrive. When I turn on the fresh water the system starts pumping but will not pressurize. While on the rack I heard water pouring out of the exhaust on the outdrive (engine not running). I turned the fresh water switch off and the water stopped. Could this be the water heater allowing water to go to the engine. If so could salt water pass from the engine into my fresh water system? It's never done this before and I believe all hoses are connected correctly although I did just disconnect them all to remove the head and I changed out most of the hoses. Thanks for your time.
