Expert: Everett Peacock - 1/10/2010

Question
QUESTION: What would cause a v8 mercruiser 228hp to overheat when waterflow is perfect and it runs like a dream?

ANSWER: here are the items to cool the engine...from most likely to worse .. Stern drive water pump, exhaust manifolds and elbows.. thermostat, leaking head gasket, transom water passage blocked..

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QUESTION: Have checked all mof the above very frustrated !!!!!  do you have any other possibilities or ideas.????

Answer
I had a Mercruiser with that same problem, I changed the engine and the problem was still there....I put a thru hull pickup for the water to go thru to get to the sea water pump...It solved the problem...what can happen is on older drives the water passage gets corroded up and will not let enough water go thru to cool it..