So, I decided to check for leaks and loose fittings and lines before splashing the boat this weekend, at some point the muffs slid off the outdrive and the impeller in the sea water pump ran dry, I think it was only a matter of seconds, so, I am sure the motor is fine [closed loop cooling] but, I pulled the lines off the sea pump and checked them for restrictions or debris and they seem fine, also, when I run water "backwards" through the suction hose, water pours out the outdrive, so, I am pretty much positive I smoked the impeller in the sea water pump? I have been told by a few people that it doesn't take long when you run these things dry to chew up the impeller.

I have looked at the pump and its pretty easy to get to, its in a 24ft Outlaw, so, I can get to it from "up top"

Can I just spin the 4 bolts out of the back of the pump and change the impeller with the sea pump in the boat? or do I have to take the entire pump off to change it?, if I can leave the pump bolted up, do I have to loosen off the belt?, or does the input shaft for the impeller run straight through?

It looks like a pretty simple fix, but, figured I would ask here first, BEFORE getting into anythng over my head. I have been pricing the impeller rebuild kits and they aren't real expensive, but, there is a big difference in price from place to place, anyone know the cheapest place to buy them?, or have one lying around?

THANKS! again for ANY/ALL input!!

Michael

If it only was a few seconds ,,i think u be fine .

Just check if the pump is sucking the water from the muff's in and u can tell if the impeller is bad or not !!

I just did this on my twin small blocks in my Sonic 28. I pulled the belt off, took the whole pump out and replaced both gaskets and a wear plate that came with the kit. There is no way you can put the impellar in with the pump in the boat. Take the extra time and pull the pump and do it right. You will thank yourself later. Its a pretty straight forward job. best of luck.

I just did one of mine last week. You can prob do it with the pump still installed, however it's easy to get it off and it makes it a much easier rebuild when you can set it on a bench and see what you are working on. It is a very simple repair. FYI. Be sure that you know the direction of the motor before you squeeze the impeller in.

we just pulled the housing off the back of the pumps on ours. took us longer but the pully was safety wired so i didnt want to mess w/ it. next yr i am cutting the wire & goin in from the front.

shouldn't you be replacing the impeller's every year anyway? I have noticed the impeller blades that are pressed against the housing take a set over long periods of not running and then the blades fracture or break off when the pump is once again turned!

I had an engine builder put a flow meter on the impeller and it was fine, at least it was til I ran it BONE dry!

I did try to hook the muffs back up and fire the boat, ran for about 2 seconds and no water out the exhaust, so, I am pretty sure its toast, there was also little chunks of rubber in the line, so, that CAN'T be good.

Sounds to me like it would be easier to just yank the whole pump off and put the impeller in on the "bench"? I assume I should check and see which way the "fins" have to face before putting it back in?, its a single 454 with the sea water pump on the same side as the helm, if anyone happens to know off the top of there head?

Also, would anyone have a part number from Mercury for the rebuilt kit?, problem being, the boat is at my cottage 2 hours away, and, obviously, so is the impeller, and all the marina's around here want me to bring it in so they can "match it up", so, a part number I can use to order one would be GREATLY appreciated!!

Thanks!
Michael

Is it a stock Mercury water pump? Also plastic pump housing?

You will find what you need here!

www.cpperformance.com

I would get you a link to the exact page but their website appears to be down

I do my Donzi with the pump in the boat and the Formula I take the pump off because it has offshore motor mounts. It can vary from boat to boat the best way. I ran a pump for about a min with no water and took it apart to find out that it was fine. It depends on if there is any water in there when you are running it and at what RPM. It will take a LOT longer then 2 seconds for you to get water out the exhaust even with closed cooling. I would with out a doubt check the thing, it is easy and the piece of mind out weighs the worrying about it tell you do. I replace my water pumps on even years so I did them last year and will do them next. It is easy for me to keep track that way.

Yes, its a stock Merc pump, serial number on top of motor has "yellowed" and I cant read it, which sucks, since that seems to be what is used to reference a lot of parts!

My pump is the plastic style with the "1 piece" rear housing, looks pretty easy to change, might have a crack at doing it myself, IF I can find the impeller kit somewhere reasonable, if not, well, its back to "Bullet Engines" who, by the way, have treated me, VERY, VERY well!

THANKS AGAIN! for all the help guys!