i have a 98' 454 mercruser with a bravo-3 out-drive.......
i changed the water pump this season but its now over heating after a couple of trips out.....,,,,
i disconnected the incoming hose to the thermostat housing and theres no water pumping up into it....all sea cocks are opened..........
my question is, can it be a defected water pump, or is there another one in the lower unit of the out-drive itself that i should be thinking of changing and if so, how do i know for sure BEFORE i yank the boat out of the water???????

there is no pump in the drive, did the impellor come apart ? if so the peices can be blocking the flow, the oil cooler is a good place to look first, remove it and look, backflush...good luck