wrote in message
oups.com...
I've scoured both Seloc & Clymer service manuals, and done extensive
searches on line, along with discussing this issue with other boaters
with much more experience than I have, but still haven't found a
definitive answer (but, of course, plenty of "opinions" ....

'86 Tiara 2600 w/5.7 merc alpha one, closed cooling system. Since this
engine has a raw water pump, does the pump in the sterndrive serve any
purpose, and do I need to be concerned with maintaining it?

Cheers,
Brian


How does the closed cooling heat exchanger get it's cooling water? The
engine pump is just like the one on your car. It circulates the coolant.
The outdrive pump is the same as the air flowing past the radiator (heat
exchanger). You need both, unless you have a jet drive like I do and they
tap off the jet pump for raw cooling water.