seapump preasure?

[warbrd2002]

How can you test the sea pump preasure? Ive changed the impeller and the boat still shuts down at 3000 rpms.. says seapump preasure is too low... engine runs cool. Its a 2006 496ho in a pontoon boat.. any suggestions? And any idea what the preasure should be?

[EricKelley]

In my catamaran I run about 15-20 psi with a pressure relief set at 25 psi. My water pressure is adjusted by tweaking the length of the pickups. You can get a mechanical water pressure gauge(or temporarily go to an auto parts store and buy a fuel pressure gauge) and install it in the hose after the water pump.

My guess is that you have a block in the system. I would remove and inspect all the hoses and flush them out. The fitting in the transom assembly can be a common restriction of water flow. I have never been in one of the heat exchangers on those engines but I know they can get stopped up as well.

I assume you have checked the impeller. The seals on the water pump shafts can go bad, but in my experience when this happens, the pump won't even prime at start. Good luck!