It is a belt driven pump on the front of the engine. It is serviceable.

"Jake S" wrote in message
oups.com...
My son has a 2000 Four Winns with a 5.7L V8 Volvo Penta (with the dual
props) and it over heats when there is a large group of people on the
boat and under throttle. The first thing I would check is the
waterpump impeller. I read somewhere that that Volvo Penta doesn't
have one in the outdrive (as my OMC or Old Merc did) - If that is the
case - where is it and can a boat owner with mechanical ability check
it? Are there any other suggestions as to what could be causing this
problem? He bought it used earlier this year - it runs great and he
has done nothing to it.