How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

[phillyg]

I posted this question on another forum but am repeating here to see if I get some other responses: I've seen posts about replacing stock Mercruiser pumps with a crank-mounted version. In my case, my starboard engine needs to be uninstalled and lifted about one foot for the tech to access the pump! I would like to be able to service the impellers myself without resorting to extreme measures, particularly my starboard engine. However, I have not been able to find definitive instructions anywhere about how to do this mod. For example, I know the hoses have to be re-routed, but what happens to the old pump housing and pully? Will the existing serpentine belt still work, or does it have to be re-routed, and how? Any other issues?

I would appreciate any guidance or direction from you great folks.

Thanks, Phil G

 

[Don S]

Re: How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

What are you working on? Be specific, make, model number, year, serial numbers if you have it.
I've never heard of a Mercruiser using a crank mounted raw water pump.

 

[phillyg]

Re: How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

That would be 2005 5.0mpi motors installed in a 1993 Rinker 300v. I have observed posts discussing using crank-mounted pumps on many Mercruiser motors, but have not found specific instructions on how to do so. I have located a variety of pumps and brackets that will work, and I know I have enough room in front of the motors to do my install, but I don't know what to do with the existing pump and if I have to reroute the serpentine belt.

 

[dan t.]

Re: How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

Why not use a Volvo Penta pump set up, they are mounted to the front pulley ,all you would have to do is hook up the hoses, probably would have to splice in V P hoses. As for the old pump take out the impeller and leave it there as an idler.

 

[fibersport]

Re: How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

I would agree with dan t, but to clean things up I would consider removing it as long as you could get a shorter belt. Since you mentioned a serpentine belt, I can understand your concern. I guess it really depends on the location of your pump and how it would affect the wrap of the belt on the pulleys. If you could post a picture or even a sketch it would be helpful.

 

[cr2k]

Re: How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

as far as a shorter serpentine belt goes the only things that need to go the same direction as the crank is the circulation pump and the PS pump the alternator does not care which way it turns.

 

[Don S]

Re: How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

 

[phillyg]

Re: How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

Thank you all. Because I can't get to the pump to remove the impeller (and thus leave the pump in place as an idler pulley, I'm going to try to find a shorter belt replacement. Don S, the diagram really helped.

 

[Don S]

Re: How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

The belt part number for the belt shown without the raw water pump is Mercruiser PN 57-865615004

 

[prbourget]

Re: How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

I have a 2000 sea ray 180BR with a 3.0 Mercruiser Alpha one. I determined that I have to change the circulator pump. Thing went OK until I could not get the bottom bolt of the pump out. The problem is made worse by the fact that I cannot get the pulley off (the motor mount is in the way). Anyone done this before? I have tried all the rusted bolt tricks (except heating the block with a torch). The pulley limits my options of getting enough leverage to break that bolt loose.
Any help would be appreciated. I am calling Doug Russell to see what they say.
View attachment 158207

 

[Fishermark]

Re: How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

It will be necessary to start a new thread of your own with your question.

 

[Eric 3.7LX Alpha 1]

Re: How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

I hate reading all the way down to the bottom of a thread to find out it's been hijacked with a new question.

 

[fibersport]

Re: How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

Did the OP ever do this mod? I like the idea of a crank mounted pump, no belts to worry about like older engines with gear driven pumps.

 

[ktbarrentine]

Re: How Do I Replace Mercruiser Raw Water Pump with a Crank-mounted Version???

Hope this guy starts a new thread.... and who the heck is Doug Russel???
@Eric...now-a-days I always look at the starting date of the post before I open it...If its "old", I go right to the "last post" option to see who's hijacking it.
KTB