If you have a brass raw water pump (Mercury) read...-gctid374875

[Go Aweigh2452]

Monday I changed out the antifreeze and rebuilt my 9.9 carb. I started the 6.2 up to make sure my spark plugs, rotor and cap were done right. She started on the first touch of the key. As she started to warm up the water temp suddenly went to 205 and I shut her down. It was either an air block from the antifreeze change or the impeller. The 6.2 needed its impeller changed out. Thought that would be simple (Not) because its hidden behind the Gen Cool Fuel II system... and then the bad news...

So much for having a brass raw water pump. The impeller is in good shape so I can assume I had an air block in the engine from changing out the antifreeze and that drove the temp up to 205. Getting back to my brass pump, it is significantly worn where the impeller has grooved the inside of the pump to a point where Kitsap Marine suggests strongly to replace the entire pump ($658+). The problem with that is the factory pumps are significantly back ordered and I have to wait at least two weeks (after 1 May) before the order will even be taken and then wait for it to be shipped...

From my understanding speaking to my Marine rep, the brass pumps service life has been around 200-300 hours and mine has well over 400 so in that regard, I am fortunate it lasted this long. And of course, there is no plastic replacement for this pump...

So, anyone with a brass pump and more than a couple hundred hours on her, better start thinking about a backup/replacement soon...

[Guest]

The plastic unit can't replace this one>?

[Go Aweigh2452]

Nehalennia wrote:
The plastic unit can't replace this one>?

Nope, believe me, I asked. I also asked about third party brass pumps and they don't know of any but that tweaked them into deciding to look and give me a call back if they do have one from a third party. They 'heard' that there was one in the works since so many Mercury brass ones are out there now...

The difference on the current brass pumps is they have an air weep hole and plastic does not.

[Guest]

Much cheaper than Kitsap Marine:

http://www.michiganmotorz.com/mercruiserquicksilver-water-pump-fittings-p-1399.html

[Go Aweigh2452]

Astral Blue wrote:
Much cheaper than Kitsap Marine:

http://www.michiganmotorz.com/mercru...gs-p-1399.html

Nice but won't work...

Mine requires the air purge system which MI Motors specifically states it does not have on that unit you highlighted... Thanks for trying...

A friend has offered to try to mill it down for me so I can have a possible spare for future use...

[BLCarl]

Sounds like a product the aftermarket could make some money on if there were many around. Start up costs would be high but after that it would be easy money especially if it could be reproduced in plastic or aluminum. I can't imagine it should cost almost as much as a refrigerator. someone's trying to get rich on us.

[Guest]

Entire pump assembly is $436.46 at www.boatfix.com

[Go Aweigh2452]

FL Dave wrote:
Entire pump assembly is $436.46 at https://"http://www.boatfix.com" wro...ww.boatfix.com

Not for the one with air purge system...

Anyway, Thanks to Rick (Bounty), I did find out I can mount a crank shaft pump on the engine eliminating the need for belt and makes it easy to change out the impeller. As long as you have 6 inches in front of the engine, this design works well. Several companies provide them and they run about $150-200+ plus new hoses so that seems a good alternative. I'll be making a run to see my local Merc mech and ask if it is feasible and what negatives there are on this arrangement. I'll also ask about how important the air purge is... so many questions...

later today...

Went down and spoke to the Mercury rep here in Port Orchard face to face. He said it is doable on my Horizon engine with air purge system but we'd have to seal off the access to the air purge for the original raw water pump. The other issue is the depth of the crank shaft pulley in that it is deeper than older Merc engines. I measured mine and would need a 1/4" spacer to clear the throat of the crank shaft pulley. The recommendation is to go with Johnson pumps. The bigger one they sell (smaller one retails for about $200 but can be found for less on the street). The other concern is since the original water pump will be gone, I would have to find a serpentine belt to fit and again the rep said it is possible for an Alpha 5.7, 5.0 or even the 4.3 belt to fit but will verify by measuring the size. Sooo, will let you all know when I am done researching this and verifying before posting more info on this project.

Thanks again to Bounty and Papa Charlie for the lead and information...

[Guest]

My bad. I thought there was only one type of Mercury brass raw water pump used on your engine. What is the "air purge" pump anyhow?Mercury OEM w/air drain 862914T11 $436.46 at www.boatfix.comMercury OEM w/o air drain 862914T10 $294.55 at www.boatfix.com

[img]/media/kunena/attachments/vb/678966=26897-862914T11.jpg[/img]I am interested to hear what model crankshaft pump you finally go with. It surely is a pain to change the impeller on the OEM pump.

[Go Aweigh2452]

FL Dave:

With air purge system: http://www.boatfix.com/shop5/store/v...dProduct=30727 On sale for $548, regularly $658...

Air purge allows me to use an air pump on top of my engine to blow all the raw water out of the engine, thus I can winterize it in about 45 seconds... Here is a photo of the engine with the air pump in its bracket. The purge gets rid of the water in the impeller so the housing does not freeze and crack in freezing temperatures. The down side is the pump is obviously expensive... and not many are out there. Thus the cost is higher than the average pump...

The brass nipple on the right side of the photo behind the blue air pump is where I attach the air pump, pump a few times and watch two pop ups indicating that the engine is charged and water has been evacuated.

[Guest]

Doug

There is only one type of brass pump that was installed by Mercury on your engine. I thought you would realized that when you went looking for the "other" brass pump.

I am very familiar with the air actuated single point drain system... I have two of them. Don't forget to open the blue plug on the heat exchanger after the indicators pop up or you don't get a full drain.

Just trying to help out a fellow boater with the best price for your pump I knew of. Even took the time to include an exploded diagram of your pump and link directly to the page to purchase it at the stated price.

You can lead a horse to water, but you....

--

Anyhow, please post pics, part numbers, etc of the crank shaft pump you decide to go with. I may go that route when I get tired of dismounting my pump and pulling hoses just to change the impeller.

Happy Boating!

[Guest]

Forgot to add after re-reading:

You threw me off when you wrote you had installed an air purge pump. But the photo shows a stock setup. I think you are a bit confused on how this system works.

The stock air drain system does not purge or blow out anything out of the raw water cooling system. The pop ups only indicate that the drains are open. Gravity does the rest. That is why you have to open the plug on the heat exchanger to let air in at the highest point. There is no air charging of the raw water system. You only get all of the trapped water out of the pump impeller by turning the pump over with the drains open. There is no purge of the pump impeller. Only gravity.

The only reason, other than convenience, that requires the air operated drain pump is if you can not reach the two blue plugs on the pump. Opening these two plugs does the exact same thing as using the air operated drain.

When the time comes for me to replace a pump, if I don't go the crankshaft mount route, I will probably go with the pump without the air operated drain. It is less complicated, easier to change the impeller, and less expenses at $295.

[Go Aweigh2452]

FL Dave wrote:
Doug

There is only one type of brass pump that was installed by Mercury on your engine. I thought you would realized that when you went looking for the "other" brass pump. [COLOR]#ff0000 wrote:
I did realize that... I was quoting one source for the new pump. Not saying I was buying that one at MSRP![/COLOR]

I am very familiar with the air actuated single point drain system... I have two of them. Don't forget to open the blue plug on the heat exchanger after the indicators pop up or you don't get a full drain. [COLOR]#ff0000 wrote:
Yep, part of the maintenance procedures that I do every layup since I installed this engine in 2007.[/COLOR]

Just trying to help out a fellow boater with the best price for your pump I knew of. Even took the time to include an exploded diagram of your pump and link directly to the page to purchase it at the stated price. [COLOR]#ff0000 wrote:
Thanks[/COLOR]

You can lead a horse to water, but you.... [COLOR]#ff0000 wrote:
A little uncalled for. No reason to be rude FL Dave[/COLOR]

--

Anyhow, please post pics, part numbers, etc of the crank shaft pump you decide to go with. I may go that route when I get tired of dismounting my pump and pulling hoses just to change the impeller. [COLOR]#ff0000 wrote:
I certainly will like I do for almost every project I have done to my boat.[/COLOR]

Happy Boating!

FL Dave wrote:
Forgot to add after re-reading:

You threw me off when you wrote you had installed an air purge pump. But the photo shows a stock setup. I think you are a bit confused on how this system works. [COLOR]#ff0000 wrote:
I did not install this factory installed air purge system on this engine. I knew what I was buying when I ordered it from Doug Russell.[/COLOR] [COLOR]#ff0000 wrote:
Sorry if you mis-understood my post.[/COLOR]

The stock air drain system does not purge or blow out anything out of the raw water cooling system. The pop ups only indicate that the drains are open. Gravity does the rest. That is why you have to open the plug on the heat exchanger to let air in at the highest point. There is no air charging of the raw water system. You only get all of the trapped water out of the pump impeller by turning the pump over with the drains open. There is no purge of the pump impeller. Only gravity. [COLOR]#ff0000 wrote:
Yep, just make sure you open the heat exchanger blue plug within 30 seconds of having the green indicator pop ups in the charged position.[/COLOR]

The only reason, other than convenience, that requires the air operated drain pump is if you can not reach the two blue plugs on the pump. Opening these two plugs does the exact same thing as using the air operated drain. [COLOR]#ff0000 wrote:
Not exactly, for storage, according to my maintenance manual:

On models with a seawater pickup pump, remove the two blue drain plugs. If the seawater pickup pump does not have blue drain plugs, or you are unable to access

them, loosen the clamps and remove both hoses.

.[/COLOR] [COLOR]#ff0000 wrote:
You need to get all the seawater out of the engine, particularly for storage layups.[/COLOR] [COLOR]#ff0000 wrote:
Not really necessary to pull those two blue plugs if you are in between boat trips in season and if you flush your engine as I do with saltaway after each trip. You must open these if you are boating during freezing weather.[/COLOR]

When the time comes for me to replace a pump, if I don't go the crankshaft mount route, I will probably go with the pump without the air operated drain. It is less complicated, easier to change the impeller, and less expenses at $295. [COLOR]#ff0000 wrote:
Hence my research into this option thanks to Papa Charlie and 2850Bounty...

[/COLOR]

Hope the above helps answer your concerns... And the completed project will be posted on my website and in the correct forum shortly...

[2850Bounty]

FL Dave wrote:


I am interested to hear what model crankshaft pump you finally go with. It surely is a pain to change the impeller on the OEM pump.

Dave, if Doug can make this work, the crankshaft pump could be one of three.

Could be the Jabsco large pump, could be the Johnson F6B-9 or Sherwood large volume pump.

All mount in the same way, all ports are configured in the same orientatio and are of the same OD/ID... or very close.

All three are good pumps, all three use the cam, all three use close to the same shaft bearing arrangement.

The Johnson pump impeller is probably easier to find.

There is also an advantage to the Johnson pump re; impellers.

Nut shelling this for the large volume pumps:

Johnson's large pump impeller is 1.900" in width.

Jabsco's large pump impeller is 1.990" in width.

Both are splined shaft indexed..... and both look, smell and feel almost the same.

But there is a .090" difference in impeller width. Narrow impeller in wide pump body = no cooling water! And believe me, this does happen when the parts counter guy gives us the wrong impeller.

Jabsco's large volume pump impeller cannot be as easily or accidentally installed in a Johnson F6B-9 pump.... so I'd go with the Johnson F6B-9 if I were making this adaptation.



The Sherwood P105 is very similar.



The base unit mounts and supports the pump into the harmonic balancer, and drives the pump shaft.

Any of these could have the shaft pressed from the base unit, and a new base unit could be made.

Or... you tool out the center, make an extended bushing arrangement, and reinstall the shaft into this bushing.

Now you have taken care of the depth issue with the pulley.

Piece of cake for a good machinist!

.

[Guest]

Thanks for that info Rick. I am going to file that away for future reference.