Gotta pic some brains here I am lost!! 06 Conquest 525 EFI Closed cooling system. Pulled this boat in couple weeks ago with smoked rubber parts on exhaust. It has headers. Rebuilt sea water pump,replaced 4" on headers and the 180 1" pipes on top of headers.I can stick water hose directly into sea water pump and get water out exhaust but the right side runs warmer than the left. Took to lake this eve and submerged outdrive and water never came out of exhaust.Kept hand on pump and header started to warm up too much Shut engine down.I have flushed the system and feel I have located nearly all parts of the old impeller.Water inlet on top?? This thing has whipped me Thanks Gus

I had to unclog a friends drive. He neglected
To flush it and there was an amazing amount of salt plugging the drive.
Can you use the hose and blow water
From the pump out through the pickups in the drive?

You really should try to track down all the pieces.

DO you have a factory water pump?

If so, did you do an impeller and wear plate- or did you go all the way and replace your pastic housing?

I'd replace the plastic stuff with a steel/brass pump (like a hardin)

Uncle Dave

Verify the hoses are hooked to the correct ports based. Sometimes they need a prime, unhook the intake enough to allow lake water into the hose and try to direct it into the pump. Then reconnect and try again.

Water does flow out the foot when I put water back thru it with a hose very freely. Did replace all parts,but will upgrade to hardin housing.Will try priming,but is there a sfee way to insure a this will not happen again when I turn it back over to the owner?? I really appreciate the input. Counter clockwise is lefthand rotation??? Thanks again Gus

Take off your outlet hose and start it up for a second (out of the water of course). If you do not get water out of it there then you have now taken a HUGE amount of the possibilities out. Then start to work your way in one direction or the other.

Sounds familiar.
Take off the end caps from the closed system heat exchangers. Front and rear. Clean out the ports. I use a small wire to clean out the rear ports and push the wire gently all the way through every hole. Then check your outdrive intake elbow, right by the inner transom plate. Hard to get to, but there is a Merc bulletin somewehere, that elbow is prown to corrosion and will restrict water flow.

i did the same thing one time and got the intake and discharge hose crossed.

did you check the elbows on the drives.

mine were so restricted that it would pump water at an idle but would starve the motor for water and burn out the exhaust.

Will check all of the above. This appears to be a all new motor and outdrive. I have little info on boat. Came from Lake Havaseu?? Stolen motor and outdrive stolen sat since 08 and presumably re rigged recently and sold. Is there a bockflow device that would hold prime on the pump? I taped off front inlet on foot and still can not get water to come up to pump. Should I be getting water like this?? Water will flow down the inlet pipe with a water hose with no restriction. Keep them coming as I will try every idea you have. I know the owner is ready to hit the water as his maiden voyage was 1/2 mile!!Thanks again Gus