I have a 1989 omc king coba sterndrive 7.5 liter engine. On land with muffs it seemed to cool fine and held a steady temp of 180 degrees. apparently there is an upgrade on the cooling system. It has a heat exchanger on top of the motor and there is no thermostat.I had it put in the water and ran it for the first time this season and it heated up to about 220.First thing i did was pull the hose of the oil cooler where the water first comes in from the stern and there was nothing but a couple of spritzes. Replaced the the water pump with kit from omc and still can't get a steady flow just a few squirts and then it looses its prime it seems like by the way the impeller i took off was not in too bad of condition and is it normal to get exhaust blow back through the raw water lines when no water is pumping through.
