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

[hpeer]

I can only relate a similar problem I had and the solution.

A Volvo MD7 which has some seriously weird fittings. The engine had heen completely rebuilt just before I bought the boat. Long story short, I had an intermittent air leak on the suction side. The damn thing would run for days fine and then overheat within 10 minutes. I could stand there and watch the temp gauge go up. It took forever to find the culprit which was a missing copper compression washer.

I am not suggesting you have a bad compression washer, that would be silly. I am suggesting that there may be some air leak on the suction side that is intermittent.

My symptom was that the engine would run fine, and then suddenly overheat. Your symptoms sound similar. It is an intermittent problem, buggers at best.

To test this you would run a bypass hose from seacock to the pump, bypass everything.

It could be a cracked hose, or a cracked strainer, or who knows what. Recently I had a hose barb leak under pressure because the barbs had been dinged by a knife. That could do it.

But I do feel for you, having felt the same frustration. I have a saying “You are not truly a cruiser until you have sat in the cockpit and cried.” Welcome to the club.

[jamhass]

When you rebuilt the water pump">raw water pump, did you check the inside of the cover for wear? It is surprising how a bit of wear can reduce the flow.

If showing wear, you can sand it flat. Wet sanding on a glass plate works great.

Similarly, some pumps have an inner wear plate that should be checked.

PS: Not true for a "speedseal".

[Simi 60]

Best thing I ever did to my Genset was to blank off the raw water pump and replace with this exact one
Several years trouble free.

Use the same model pump as feed pump for watermaker.

https://www.ebay.com.au/itm/MD-30-Ma...edirect=mobile

[Tspringer]

Originally Posted by gonesail

the owner did state that he thought the engine would need to be removed from the boat to work on the exhaust elbow.

I am thinking an easier solution would be to somehow cut part of the exhaust elbow off. If even a section of it could be cut away access could be gained to an impossible bolt allowing the rest to be removed. When re-installing a new one all it will take is positioning the elbow mounting slightly differently and bolt access will be fine. The problem is not the generator design itself.... it is the brainless installation.

[hpeer]

If you intend to keep the boat them you will need to face that situation sooner or later. And if you intend to sell at some point in the future then the “fix” becomes a “feature” and sets you apart from others of that make/model. So I see no downside to that approach.

OTOH, if you cab cruise successfully with just the Honda then you can loose that weight and the fat ass. Anytime you reduce complexity you improve happiness.

I still believe your problem is related to a suction side air leak. But I also believe you would be a happier man without the iron beast. Perhaps the compromise is to invest in some wind/solar and/or upgraded batteries?

One way of looking at the problem is your gennie does not work.

The other way is to consider you are using too much juice.

Perhaps a sweet spot can be found in a compromise solution?

In any case the best of luck. Please keep us posted.

[chris95040]

Originally Posted by Tspringer

I did do this and it does pump more water when I first flipped the impeller cover but looking at the water coming out of a hose into a bucket and looking at the water coming out the exhaust is much the same thing.

You don't own a watch?

[more]

Originally Posted by jamhass

When you rebuilt the raw water pump, did you check the inside of the cover for wear? It is surprising how a bit of wear can reduce the flow.

If showing wear, you can sand it flat. Wet sanding on a glass plate works great.

Similarly, some pumps have an inner wear plate that should be checked.

PS: Not true for a "speedseal".

first, watch this. start engine make short movies best in a sunset. raw pump is also possible check. if something wrong in pump,pump be hot and cover plate paint be burn.

https://www.youtube.com/watch?v=fLzkqNPHo0Q

what I work for one client recently

[more]

not that the heat exchanger was full of limescale and clogged but the hose from the heat exchanger almost to the sea pump was full of rubber parts of the impeller. The sea pump is also running out but there is no more money, the original Korean is around € 400. But I think it will last 1 season
O rings are not original, but universal, but again 4 O rings is 60$ Stud is not volvo penta but Catepilar only 18$ kn all 4.
only the thermostat is an original volvo penta, everything is from other original manufacturers but you need to know the serial numbers of the original OEM parts.

You say, you clean heat exchanger. How. i use a big bath pool full of citrus acid 24 hours. later ultrasound cleaning in hot water 180 minute. Later close all intake with special toll and compress with air and bath in water for seeing leaking.

[Tspringer]

OK.... BACK at it on trying to fix the nightmare Westerbeke.

Back in April I basically quit trying to fix this thing as it just proved impossible in the Bahamas and my frustration boiled over too much.

Now we have been back at the dock on shore power BUT we hope to head out soon for some cruising over the next year and need the genset to work. I had divers inspect the raw water pickup from beneath the boat, they see nothing wrong same as my inspection in the Bahamas.

First thing I did to get started back on this was to completely remove the raw water hoses between the thru-hull and the strainer and from the strainer to the generator raw water intake. I also removed the strainer. With no hose attached, when the raw water intake valve is opened water pours in at an extreme rate indicating no obstruction at the thru-hull intake.

I inspected both sections of hose including with my nifty new cell phone connected endoscope. No issues with either section of hose noted - both are free from any obstructions. The strainer was also cleaned and closely inspected for cracks and nothing was found.

So no hose issues located before the raw water pump. This pump has been freshly rebuilt.

So what next?

I am considering attaching the long piece of hose I removed from the thru-hull to the raw water intake connection on the genset leading to the raw water pump and then connect my fresh water hose to the other end of the raw water hose and try running the genset this way to see if it makes any difference. IF the pressurized fresh water results in plenty of water flow out the exhaust this would seem to at least rule out issues with the exhaust elbow and giant diameter exhaust hose.

Could this cause issues such as the water going in at pressure backing up into the engine somehow?


I have read suggestions about measuring the water going through the pump and then measuring the water coming out the exhaust to see if there is an obstruction at the exhaust elbow but my exhaust fitting on the hull is close to the water line and there is no means of getting a bucket in place to catch all the water coming out unless the bucket is somehow forced under water with just the lip above. Attempts to do this failed to result in any accurate means of measuring the water output from the exhaust. To do this accurately the boat would need to be hauled out.

I have not tested the rebuilt raw water pump specifically as doing so would require running the generator without any cooling water flow at all for a bit at least. BUT - I can do this test if those who know more than I do agree this will not cause harm.



QUESTION: Could the issue be with the hoses that go to the vented loop? The raw water leaves the heat exchanger and exit back out of the generator hosing to a vented loop before coming back into the generator housing and going to the exhaust elbow connection. Blowing into the hose attached to this vented loop results in bubbles sounds from the cooling header tank. So the vent is not blocked. I cannot see anything to indicate any issues with the vented loop or hoses.

Getting this thing fixed must be complete before we can leave the dock. ANY suggestions are hugely appreciated!

[more]

Originally Posted by Tspringer

. ANY suggestions are hugely appreciated!

yes, hire a .professional mechanic.

[jakkum]

I did not Read all but thought IT could be about hoses.
These things most of the time have different lagers and if they het seperated, it is possible that the inner later, because of a small internal leak van be bloem OR sucked in such a way that it blocks the flow. Found this several Times with old hoses that still looked perfect.

[PeterBernard]

Your test this time round with the raw water hose between the inlet valve and the pump was incomplete.

It sounds like you tested for blockages and visual damage, but if you remember from my post back in March, the problem was the hose betweens strainer and pump COLLAPSING under suction pressure. This was not visible, either with the hose removed, or under operation.

Replacing these hoses (from inlet to strainer, and strainer to pump) is a 5 minute job with an appropriate dimensioned reinforced hose, and given that my Genset is identical to yours, had the same problem, and I tried everything you did (and more - I was able to remove the exhaust elbow), I'm convinced this is worth the minor effort and expense.

To make the job easier and quicker, you can bypass the strainer and just go direct from the inlet to the pump for testing purposes.

Go on - give it a go. But put a couple of beers in the fridge first, ready to send to me nice and chilled later today 😁

[Nicholson58]

I have had hoses delaminate. They look OK but a vacuum applied collapses the interior.

[Tspringer]

Originally Posted by PeterBernard

Your test this time round with the raw water hose between the inlet valve and the pump was incomplete.

It sounds like you tested for blockages and visual damage, but if you remember from my post back in March, the problem was the hose betweens strainer and pump COLLAPSING under suction pressure. This was not visible, either with the hose removed, or under operation.

Replacing these hoses (from inlet to strainer, and strainer to pump) is a 5 minute job with an appropriate dimensioned reinforced hose, and given that my Genset is identical to yours, had the same problem, and I tried everything you did (and more - I was able to remove the exhaust elbow), I'm convinced this is worth the minor effort and expense.

To make the job easier and quicker, you can bypass the strainer and just go direct from the inlet to the pump for testing purposes.

Go on - give it a go. But put a couple of beers in the fridge first, ready to send to me nice and chilled later today ��

Peter,

I do agree with you and I will be replacing all of the raw water intake hoses tomorrow.

I also tested the rest of the raw water system by taking the long intake hose and attaching it directly to the raw water pump intake and then the other end to our fresh water pressure hose. As I turned the generator on, my wife held the hose nozzle into the raw water hose and gave it full blast. The water coming out the exhaust was significantly more than what the raw water pump was able to generate alone. The generator ran for 20 minutes and never went over 170 degrees.

This leads me to think the water injection fitting at the exhaust elbow is not the source of the problem.

So I am going to replace all of the intake hoses and test again.


here is a short video I did last March showing the incorrect low water flow that results in overheating:

https://defensivedriveracademy.nyc3....20Output-1.m4v


This video shows the water flow from the exhaust today with the pressure water hose being applied:

https://defensivedriveracademy.nyc3....20163547-1.m4v

[Tspringer]

As it turns out getting 1" ID reinforced high temp exhaust hose like the hose being replaced is all but impossible as nobody has this hose available. At least not if I want it anytime soon.

So I ordered some clear PVC wire reinforced hose designed for high pressure or suction. This hose is not temp rated like the black hose it will replace but given the use for raw water delivery to the pump, it will never be hot. Also - given that it is not laminated hose it will be impossible for the hose to delaminate in the interior sections and with clear hose any obstruction can hopefully be seen.

So now I wait a week or more for the hose. The people who sold me the raw water pump rebuild kit also offered to check the pump for me so I will likely be sending it off to them.

So this project will be a few weeks before more progress is made.