Raw water system issues.

[ToddH]

Hello everyone I'm new to this site so just bear with me but I have a 1969 Cal 230 Jensen sailboat equipped with a universal diesel m4-30 motor my raw water system is having issues cuz I noticed that there was no water coming out of my exhaust in the back of the boat I checked the strainer in the in the container and it was full of seaweed and seagrass so I cleaned it I changed out the impeller cuz it was shattered into like a hundred pieces I checked the heat exchanger and it looked like it was a little bit clogged so I took a coat hanger and cleaned it out as best as I could and the exhaust elbow seems to be okay and so does this big old round black thing that's labeled in and out as far as the exhaust goes but it is still clogged there's still no water coming out of the back and the engine is still overheating I am stumped and at a loss and I don't know what else to check or what else to do in this case is there anybody here that can help me with this because I can't continue boating with my kids unless I fix this problem and I don't know what else to do any ideas?

 

[capta]

The first thing I'd do is take the hose off the seacock. Be sure to have the valve closed, as you are doing this and open it very slowly to see if you have water there. Next, do the same at the sea strainer outlet. After that is the seawater pump, again the hose off the outlet side. Then the outlet from the heat exchanger, etc to the hose entering the exhaust elbow. However, remember it only takes a minute or so to trash the impeller if it is run dry.
If you have steam coming out the exhaust, you probably have a head gasket leak.
Good luck.

 

[ToddH]

Thank you for that input I did most of what you were mentioning already except for the exhaust elbow part I already checked I already had a diaper go underneath and clear out the intake for that I cleaned out the seats the strainer because it had seaweed and seagrass and stuff in it and then I took the my impeller when my old one was shattered into a hundred pieces so I put a new one in but if there's a little bit of water coming through the underneath the boat through the system but it's not enough to be spitting out of the back so I don't know if the impeller is not doing its job or maybe I incorrectly installed it which is kind of highly doubtful because of that little key thing that's in there other than that I've done most of what you were mentioned already so I don't know what else it could be

 

[ToddH]

Sorry that meant to say diver not diaper I apologize

 

[JoeWhite]

I suppose you can use a pressure doc water hose and push water through each section and see where the blockage is.

 

[Don S/V ILLusion]

If it is raw water cooled, you won’t get flow until the thermostat opens and if it is stuck, ….

 

[dlochner]

So far you have focused on blockage, there is another suspect, an air leak that prevents the pump from maintaining a prime. A likely suspect is the stainer. If you have one with a glass body, there is a gasket at the top of and bottom. They can develop a an air leak which will prevent the pump from pulling water through the system. There may be other connections or places that are leaking air, but not water.

 

[JamesG161]

Here is the M4-30 manual and part numbers.

Jim...

 

[JamesG161]

My guess is your new water pump impeller was not installed correctly

Jim...

 

[jviss]

I'm betting the through-hull is blocked, regardless of the diver's inspection. Take the hose off the pump, stuff it into your portable air horn, open the seacock and give it a blast. When you remove the horn you should have a pretty god flow from the hose.

 

[ToddH]

Hey everyone I finally found out what was wrong the system . Before I mention it I'm totally shocked with West Marine because we spent about a half hour by phone taking measurements and brainstorming the problem and an hour and 20 minutes in the store trying to find an impeller that fit we found one that we,me not knowing much about raw water pumps, thought would work well after installation it kept overheating and after two weeks of tearing apart everything to find out what is still the problem the guy anchored up next to me came over and asked what wrong with my boat. I told everything I've done so far and the very first question out of his mouth was is my impeller flush with the inside of the housing? Basically are some of the fins on the impeller bent I said no the fins aren't touching it at all why? He said there lies your issue. It's not circulating the waye

 

[LloydB]

" It's not circulating the waye " it appears that JamesG161 description of part number 9 must be made by unobtaineum and critical to complete the assembly properly.

 

[jviss]

" It's not circulating the waye " it appears that JamesG161 description of part number 9 must be made by unobtaineum and critical to complete the assembly properly.

No I think you're misinterpreting the OP's response. He says:

Basically, "are some of the fins on the impeller bent?" I said no, the fins aren't touching it at all, why?

(I added some punctuation to the quote to make it more easily readable.)
It seems the impeller is too small in diameter. So, wrong impeller! At least that's how I read it.

 

[JamesG161]

If had looked up the Owners Manual, like I did, and told West Marine it was the

SHERWOOD WATER PUMP NO, 302648

He would have gotten the right parts.

But...

We all had to learn about our water pumps , the first time.
Even part #9



Jim...

PS: @ToddH read your Engine manual.

 

[JamesG161]

I just upload that manual to SBO for all find in the future.

Most users do not know many manuals for General use can be found here.

Downloads

You can Upload PDF files for General Use manuals too

Jim...

 

[jviss]

Even part #9

I don't get the part #9 reference.

 

[LloydB]

Sorry my bad should have said item number on the list that James gave us. There was no part number listed for that item with the note: Not Available Order #13. The short explanation wasn't clear to me as to whether the pump wasn't circulating or waye wasn't being circulated.

 

[ToddH]

My motor says 302697 universal diesel. I got the boat for free on Craigslist and it didn't come with a manual.

 

[JamesG161]

My motor says 302697 universal diesel

Please download the manual I linked in my post#8

Universal = Westerbeke in that era

Jim...

 

[jviss]

waye

What's "waye?"