1979 OMC 305 Water pump question/ what is this part?

[doc_hall]

Hey all and thanks in advance for any help i get. I boat a 1979 cruisers villa vee with twin omc 305 engines...one of them blew and i have the short block shipping to me and i don't really know what this part is to order a new one. i called iboats and the part number....908920 is no longer made. I'm attaching some pics if any of you could please tell me what this is and if there is a newer version of the part that will work for my engine. Thank you all.

 

[Boomyal]

Re: 1979 OMC 305 Water pump question/ what is this part?

Good question. I would hazard a guess and say it is a remote water pump. Is there one for each engine? Where do the two hoses come from and lead to?

 

[doc_hall]

Re: 1979 OMC 305 Water pump question/ what is this part?

Good question. I would hazard a guess and say it is a remote water pump. Is there one for each engine? Where do the two hoses come from and lead to?

one of them came from a metal canister and we believe the other came from the block. and yes there is one on each engine. Thank you.

 

[Boomyal]

Re: 1979 OMC 305 Water pump question/ what is this part?

What and where is this 'metal canister'? Is there one for each engine? Is there any kind of access to the insides of the cannister(s)? Are there any other hoses leading to or from the canister(s)? Where on the block did the one hose go to or come from? It definitely sounds like some kind of water/coolant circulation system??

 

[doc_hall]

Re: 1979 OMC 305 Water pump question/ what is this part?

I will try and get more info from my mechanic, but i'm being told it is the sea water pump, and that part number is no longer made. This seems to be a problem with other people with older 305 and 350's.

 

[southkogs]

Re: 1979 OMC 305 Water pump question/ what is this part?

Might be the closed cooling system that was available on some OMC's. I think I've seen them available ... but can't recall where now. Might wanna' Google OMC closed cooling system.

 

[Boomyal]

Re: 1979 OMC 305 Water pump question/ what is this part?

.....Might be the closed cooling system that was available on some OMC's. .....

That was where I was leading with all my questions above, however I was not aware of any OMC closed cooling options but it makes sense for a larger dual engine cabin cruiser that is likely to be used in salt water. If that is what it is all about, I sure there must be some kind of substitute available.

 

[doc_hall]

Re: 1979 OMC 305 Water pump question/ what is this part?

I definitely have an open cooling system. The pump in question is the raw water pump, which is no longer made and there is no aftermarket replacement. I'm going to have someone rebuild it and hope that it works for me. Thanks guys for your help.

 

[Boomyal]

Re: 1979 OMC 305 Water pump question/ what is this part?

I definitely have an open cooling system. The pump in question is the raw water pump, which is no longer made and there is no aftermarket replacement. I'm going to have someone rebuild it and hope that it works for me. Thanks guys for your help.

I guess that must mean that you do not have any impellers in your outdrives?

 

[southkogs]

Re: 1979 OMC 305 Water pump question/ what is this part?

... The pump in question is the raw water pump, which is no longer made and there is no aftermarket replacement...

What HP is your drive? I'm not familiar enough with the systems after the Electric Shifts to know for sure.

BUT ... for a '79 260HP, the water pump assembly (breakout kinda' looks like yours) is available HERE for $285. You may want to look around on there to find out if yours is available - or if you can find a part number and Google that mug.

 

[doc_hall]

Re: 1979 OMC 305 Water pump question/ what is this part?

So it turns out that the easiest way to fix this issue with the older engines is to convert to a crankshaft driven raw water pump instead of even fooling with the old style. So this is what i will do. Thanks for all of your help.

 

[notordinary]

Re: 1979 OMC 305 Water pump question/ what is this part?

I'm having the same issue. I cannot find this raw water pump shaft seal. I found the impeller 18-3086 Sierra (Napa) and shaft bearing Hyatt Z995203 its $31.00 Hyatt has it. I going to do more digging to see if I can find the seal. Correct craft said if I sent them the pump they can rebuild it for me. But then I have to do both of them. And if I cannot get the parts it would be a waste of money. I think it would be better to just upgrade to a crank driven pump and be done with it.
Good luck, I'll post back if I can find the shaft seal.

 

[Howard Sterndrive]

Re: 1979 OMC 305 Water pump question/ what is this part?

I guess that must mean that you do not have any impellers in your outdrives?

I think a Villa Vee is inboards, not i/o's so that would explain the engine mounted impellers.