Dumb question. 89 454 gen 4 seawater pump..Intake on the top or bottom? If I have them backwards will I get ANY water out of it? I wouldn't think so, but I'm thinking I may be backwards, and get just a little water out of the hose I took off going to the ps cooler...HELP!

First time I replaced my impeller, I thought I had them on backwards too, so I got another longer piece of the same ID hose, hooked it up to one of the pump fittings, held the hose up high in the bilge, and filled the hose with water. Had the wife turn the motor over real quick. If the water sucks in...intake, if it flies out...lol....well, thats not the intake then !!! ( I happened to guess right...in case your wondering when I did the experiment )

Merc had them both ways, depending on the engine. Some had the intake on the bottom, some on the top. Look at the rear of the pump. The intake will say "RH out" and the outlet will say "LH out". That is for left hand and right hand engines. Yours is a standard left hand engine, so your outlet is the one that says "LH out". If you can't see it, use a mirror to identify the outlet. Good luck.
By the way, if you hooked it up and ran the engine with the pump dry, then go ahead and change the impeller. It is more than likely no good if the engine ran for more than 5-10 seconds with no water.
Eddie

I had mine hooked up wrong the first time.Just switch hoses and see.

Guess I'm swapping them ha ha..Ok, while I'm asking dumb questions, looking aft at the motor from the helm, it rotates clockwise. Seems like this would be rh rotation. Do you call rotation on a boat looking at it from the rear, looking forward? Prop spins opposite direction of the motor, I think I've been looking at this too long ha ha!

you look at the engine from the front,clockwise is lefthand.this is standard rotation.are you confused yet.

Rotation is determined by looking at the flywheel from behind. You have a LH motor and RH rotation drive.
If you have the 2 piece pump body which has the metal end section where the hoses connect it will have a 1/8" pipe plug in it above the OUT neck. Plastic 1 piece pump body do not have this plug.
FYI all Mercruiser STERNDRIVES use LH motors.

This use to confuse me too. I always looked at the way the impeller rotated based on motor rotation and it is easy to see which port sucks and which one blows!

Ok...Confusion is ebbing ha ha! I had it right the first time. LH OUT should go to the ps cooler. Swapped hoses last night, and got nothing. Soooo...that leaves checking the gooseneck on the transom plate for a good seal, which should be good, new gasket and rtv on both sides, or I smoked the impeller again. I can't imagine there being anything in the drive itself that would impede water flow. I back flushed it and water seemed to come out fine. hose from the transom to the pump looks ok, old, but nothing obvious. And there's a flush device in between. maybe a new hose without the flush device? I do get some water flow when hooked up properly, just not nearly enough to do the job...

Is the flush device open or closed? And you can get depris in the drive that under suction blocks the intake hose when you get off throttle it will open up again.