Stepped up from a catalina 22 to a catalina 27 1985 with a universal m-18 diesal, took it out for my 3rd shake down cruise, throttled up to 2300 rpm and heard a small pop, then there was exhaust in the cabin and water filling up the bilge..... Engine did not overheat and was able to make it back to the dock. Im guessing that the exhaust hose/water outtake fell off the engine and caused my problem.... does anyone suggest any other trouble shooting before I get down into the engine compartment?