i have a 500 efi running 190 to 195. new water pump impeller new water hoses on raw water pump and circ pump looks ok engine will not build water psi over 8 or 10 lbs. i have all ready cleened oil cooler and power steering cooler and sea stranier is clean. any help

You Changed The Impeller Only??

How old is the drive? Fresh or salt? Bravo drives have a hose that goes from the drive bellhousing to the gimbal housing. Check the hose for physical damage or binding. The locations where that hose connects are also a problem. They are pulled through the aluminum castings and have an insert threaded to hold it in place. The aluminum can corrode causing it to swell and create an obstruction to water flow. Did your problem start abruptly?

Rene

Yes, If you have the new style brass seapump, You probably need a whole new pump or the plate kit in it. Look inside on each end of the pump for grooves, It is probably bypassing on the ends of the impeller..

mbones, Rene is referring to where it passes through the transom plate, corrosion is common there and it swells and pinches the hose making it smaller. Also you should have changed the pump and housing together. If any connections to a flesh kit are bad that will contribute to the problem as well. Back flush through transom and drive from back of water pump, it should take a full load from garden hose. That should help narrow down problem area.
Jim

my drive pickup is just feeding the drive shower.i have a nother pickup for the engine. and yes i changed the housing, plate,o-rings on raw water pump.but the circ pump does have a brass impeller.

If you have an Offshore type pickup, it may not be low enough in the water. Your water pressure is low.

yes but the other is the same depth and its runs fine 160 dgf

Has your current set up been working or was it been changed to what you have now? It is possible the hose to pump is collapsing internally under suction. Intake hoses can fail as they age and not all hoses can be used as an intake hose. The circ pump shouldn't have any effect on your current problem of low pressure.
Jim

i changed both suction and discharge i used belloflex with stainless steel wire core