Impossible to Fix Westerbeke? 7.6BTD mocks all repair efforts!

[Nicholson58]

The only item you do not mention servicing is the thermostat. My main Westerbeke overheated Bonaire to PR. On the dock, I removed the thermostat and placed it in a saucepan with all spares and an electronic thermometer. Slowly raised the temperature and selected the quickest and widest opening of the lot. Also noted the temperature at which each one opened. Tossed all of the bad ones (2). The worst of the bunch was the one that had been in service. It did not begin to open until F220.

BTW, don’t toss any old coolant circulation pump. Find a rebuild shop to fit new bearing and seal. 1/10 th the cost of new.

[Kerryf]

Not sure if you checked the exit end of the system where the water gets injected into the exhaust.
My engine has nozzles, they were 80% blocked.

[PeterBernard]

We have the same generator, and had exactly the same problem 3 months ago.

Like you, we were at our wit's end after over a month of trouble shooting. We were also somewhere pretty remote (Seychelles) but given we're in the Indian Ocean, had the good fortune to have a whole bunch of spares with us. We also have good access all round the genset.

We tried EVERYTHING.

Checked inlet, strainers, all hoses removed, replaced thermostat, replaced heat exchanger, replaced impeller, replaced water pump">raw water pump, checked Exhaust elbow (clean), used IR heat gun throughout the entire system to try and isolate problem area. I could go on - there's literally not a single item mentioned on this thread that we did not try, and quite a few others besides.

None of them worked.

Then I mentioned the problem casually to my marine electrician mate in Australia when I was chatting to him on WhatsApp about a problem with our electrics, and he said...

"You've got a problem on the suction side of the pump - probably a collapsing hose between the strainer and the pump."

I sad "Nah, it looks fine".

He persuaded me that it could look fine externally, but still be collapsing internally under suction, and to try replacing it with some new reinforced hose.

10 minutes later, problem solved!

I owe him MANY beers (for a whole bunch of other problems he's solved for us along the way too).

[morribabes]

A blown head gasket can pressurise the cooling system to the point where no cooling water can get into the water passages. Long shot I know, but if all obvious causes have been investigated, then it has to be something that is not obvious.

[Carl-T705]

I don't have time to read 5 pages of try this, but It could actually be a collapsed suction hose . The interior wall of the hose may be collapsing when suction is applied.

[Kerryf]

I see you did check the exhaust elbow which was my first suggestion.
I have had a problem with Jabsco type rubber impellors where the bronze splined shaft spins inside the rubber vanes. They looked fine and apperared solid but under the pressure of pumping water the bond broke down.
In my case they broke due to back pressure from the blocked exhaust nozzles. 4 bar is all they can handle.

[BigNash]

Don't know if this has been suggested, but was a diesel mechanic long time ago and a number of times I have found a suction hose that had an internal separation from the outer, without suction it would flow like it was supposed to but suction would collapse the inner hose and stop flow. You can't tell by looking at it. Good luck.

[capn_billl]

I keep a 1/2", (and a 3/4") hose barb adaptor onboard with a length of flexible hose for troubleshooting for this purpose.

It saves me from yoga while troubleshooting raw water pumps.

[Kit_L]

What a nightmare! Joining this excellent thread to see what the problem was, in the end, assuming Terry does fix it. And (speaking of delamination of suction hoses: inside collapses while outside looks fine) I have seen this myself. And it could explain other problems Terry has described. Good luck!

@PeterBernard: that electrician you mention—any chance you could PM me his details? Of all the experts one needs around boats, these are the hardest to find in our area!

[skipperguy]

had similar problem with friend’s Generator. After professional repair failed but Billled him anyway. The exhaust hose had delaminated on the inside and would not flop down for blockage until the generator was running. The delamination corrected when the generator shut down and appeared normal when looking through the hose. Replaced hose and all was well

[Tspringer]

I do get and understand all the suggestions for replacing the entire raw water hose setup from thru-hull to raw water pump. I DO plan to do this as well. The entire system from thru-hull to heat exchanger will be getting replaced as the next step. The entire raw water hose from thru-hull to strainer - new strainer - new hose from strainer to generator intake fitting - how from fitting to raw water pump - rebuilt raw water pump - new hose from pump to heat exchanger. ALL of it being replaced.

I have had numerous suggestions that the issue is the thermostat. Please tell me how a bad thermostat in the fresh water cooling system is causing improper water flow through the raw water system?

Should all the planned repairs still not fix it - next step will be to remove and replace the entire giant main exhaust hose. That if necessary will have to wait until back in the States.

IF THAT does not fix it -- then the exhaust elbow will be replaced along with all other hoses. If THAT does not fix it (the entire raw water system and exhaust system would be new at that point) Then I will plumb in an electric boost pump to the raw water circuit. If THAT does not fix it - I will remove the generator and sell it.

Based on a careful reading of the entire Westerbeke generator installation guide, the raw water fittings as installed by Beneteau are too small. The 1" ID hose is fine - 1/2" ID fittings are not The strainer is also mounted too far above the waterline. So as I go through replacing everything on the raw water feed side I will also replace all the fittings that are undersized and relocate the strainer.

I DO agree with the comment regarding Westerbeke vs Northern Lights. I would not buy another boat with Westerbeke unless the installation was at least 100% to their specs but even then I feel the cooling system is under engineered. Yes, it works. But only if EVERYTHING is in perfect working condition. Perfect is hard to maintain and a standard that does not fit cruising realities.

[Kerryf]

I have also come across a situation where a zinc had expanded from corrosion and was partially blocking the waterflow.

[more]

Originally Posted by Tspringer

I do get and understand all the suggestions for replacing the entire raw water hose setup from thru-hull to raw water pump. I DO plan to do this as well. The entire system from thru-hull to heat exchanger will be getting replaced as the next step. The entire raw water hose from thru-hull to strainer - new strainer - new hose from strainer to generator intake fitting - how from fitting to raw water pump - rebuilt raw water pump - new hose from pump to heat exchanger. ALL of it being replaced.

.

This is all wrong way.
Disconect hose after raw water pump ,put similar hose in raw water pump and in bucket or outside boat.
start engine. if sea flow +- 20% in raw water pump specification problem is in heath exschanger and 99% exhaust elbow. if not problem is from raw water pump to thru hull
Disconect hose from thru-hull and put in bucket end hose with water if water don't water flow problem is stainer or ump.
after this disconnect stainer and this hose put in the bucket and check water flow etc.etc.

[skipmac]

Originally Posted by Tspringer

I DO agree with the comment regarding Westerbeke vs Northern Lights. I would not buy another boat with Westerbeke unless the installation was at least 100% to their specs but even then I feel the cooling system is under engineered. Yes, it works. But only if EVERYTHING is in perfect working condition. Perfect is hard to maintain and a standard that does not fit cruising realities.

Not sure if newer Westerbekes are the same but I have an older model Westerbeke engine in my boat and the parts are a serious ripoff. I finally discovered my W58 is the same engine as a Perkins 4.154. Compared the fresh water pump prices. Westerbeke $270, Perkins $90. The ONLY difference, red vs blue paint.

Never more Westerbeke for me.

Originally Posted by Tspringer

I have had numerous suggestions that the issue is the thermostat. Please tell me how a bad thermostat in the fresh water cooling system is causing improper water flow through the raw water system?

Thermostat will impact cooling but raw water flow? Very doubtful.

So many posts I don't know if you have done all this but let me repeat my foolproof way to trouble shoot a problem. Start at one end and verify proper function step by step, linearly, skipping no major part, assembly or connection. I understand there are problems with access in your situation but I've spent hours and hours trying to fix a problem by trying this and that, no luck so finally bit the bullet, worked down the line and within a couple of hours had isolated the problem.

[more]

Originally Posted by skipmac

Start at one end and verify proper function step by step, linearly, skipping no major part, assembly or connection. .

only this way is the proper way to find malufuction.
But with my huge experience I know is 99% exhaust elbow.
But on boat what I maintenance in some first move is installing an exhaust temperature probe.

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