4.3 water pump replacement questions

[1997StingRay190]

So this will be my first outdrive water pump replacement. The only other one I've done is on a 1969 Evinrude 115 with electric shift- so please excuse my ignorance

So the question is, are there really no cables going to the bottom of the outdrive? I can really just put the thing in forward, loosen the bolts/nuts and let the thing slide right down/off? Then its pretty straight forward when you have a pump kit what to do (I think/hope). Pretty much swap the impeller, gaskets, face or intake plate, and then just put the two pieces together? Seems to simple to be true, but thats how it always seems right before I get my *ss kicked by a first time project :redface:

I also heard you should only use a real mercruiser water pump kit, if this is true can someone point me towards the right part number for it (Alpha 1 Gen 2). Also should get some of the permatex just in case or is there something else I can use that would be available locally?
Thanks for helping the newb fellas

P.S. One more question, sorry I just thought of it. If my engine has a fresh water/belt driven pump then does that mean I don't have one of the rubber impellers in the outdrive?

 

[chiefalen]

Re: 4.3 water pump replacement questions

So it seems you read the manual, and all you have to do next is go to the top of the page and order it.

And if it is a alpha 1 gen2 then you do truly have a impeller in the drive.

Any auto parts store even wal-mart has the permetex.

Good luck !

 

[Bondo]

Re: 4.3 water pump replacement questions

If my engine has a fresh water/belt driven pump then does that mean I don't have one of the rubber impellers in the outdrive?

Ayuh,... The Devil is in the Details,... Which you ommitted,.. What Motor,..??

Alpha Gen.IIs do have a raw water impeller,+ I see No problem with using the Sierra kits available Right here at iboats...

 

[1997StingRay190]

Re: 4.3 water pump replacement questions

Sorry about that little brain fart there bond-0. The motor is a 1997 Mercruiser 4.3 LX Gen+. There if clearly a belt driven water on the front of the engine with the rest of the accessories. Does this mean I either 1. Dont have an impeller on the Alpha drive, or 2. Have one and it definitely needs to be replaced even if the system has a belt driven water pump?

Thanks again.
Sean

 

[Fishermark]

Re: 4.3 water pump replacement questions

There if clearly a belt driven water on the front of the engine with the rest of the accessories.

For boats, there is a different terminology when it comes to the water pumps. The one on the engine itself - like a car - is usually referred to as the circulating pump. Yes, your engine has one of those AND a water pump in the outdrive.

Now it is POSSIBLE that your engine has a raw water pump on the front as well - typically seen in Bravo drive, not your Alpha. IF you have a raw water pump with a through hull pickup - which I doubt, then it is possible that you may not have an impeller in the outdrive.... but as I say, that would be an unusual set up.

 

[Chris1956]

Re: 4.3 water pump replacement questions

Mark, I have been told that they sometimes used a thru hull pickup and belt driven pumps on closed cooling systems on V6 and V8 Alphas. Apparently, the drive-mounted impellers could not keep up the demand for cooing water for the heat exchanger.

 

[Bondo]

Re: 4.3 water pump replacement questions

Ayuh,...

You're Right of course Chris,...
But,..
After Mark posted,+ I reread the OP's posts,...
I now think Mark is On the Money...

 

[Fishermark]

Re: 4.3 water pump replacement questions

Mark, I have been told that they sometimes used a thru hull pickup and belt driven pumps on closed cooling systems on V6 and V8 Alphas. Apparently, the drive-mounted impellers could not keep up the demand for cooing water for the heat exchanger.

I think even then, they keep the impeller in the outdrive and either cut the hose and let it splash against the transom, or route the hose back out through the transom and dump the water back over. That helps in cooling the outdrive. For what it is worth, I have an Alpha and have a raw water pump with a through hull pickup on my boat - but as I say, I doubt that is what he has. I believe he is referring to the circulating pump instead of a raw water pump.

 

[Fishermark]

Re: 4.3 water pump replacement questions

Here's a picture of my engine showing both the circulating pump (called a water pump on a car) which you DO have, and the raw water pump which you may or may not have:

 

[1997StingRay190]

Re: 4.3 water pump replacement questions

Yep, I've only got the pump that is mounted right above the crankshaft. Its an open cooling system so I am pretty sure I need to replace the impeller.