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

[jjenso]

Seems like everyone missed checking the thermostat,it may not be opening all the way

[rbk]

Originally Posted by jjenso

Seems like everyone missed checking the thermostat,it may not be opening all the way

On a dual loop system the t-stars are on the coolant loop not the raw water side. Also OP says not enough raw water is coming out the exhaust.

[Kit_L]

The thermostat was mentioned several times in the first 2–3 pages, but it's not relevant; the t'stat is on the engine/coolant side and the problem the OP talks about is on the raw water side (of the heat exchanger). If I've got this wrong, someone please correct me.

[Tspringer]

Originally Posted by jjenso

Seems like everyone missed checking the thermostat,it may not be opening all the way

Please - How is a bad thermostat impeding the water flow out the exhaust?

The raw water flow is clearly - visibly - significantly LESS out the exhaust than it was before the overheating issue appeared.

[Tspringer]

OK -- Wife and daughter flew in and brought the raw water pump rebuild kit.

Kit ordered off ebay - the only one I could get shipped to us in time. This kit came with very poor instructions - parts all numbered on the sheet but no key to the numbers so no way to know what part is really being referenced. I assembled it exactly as the old one came apart.

No matter - rebuilt pump did NOT fix the issue. The amount of water through the exhaust remains the same.

At this point efforts to fix it here in the Bahamas are over. There is no correct 1" diameter exhaust hose in Nassau and no way to get any shipped in time to not lose the families entire vacation. I also cannot source a new strainer here.

So we will complete my season in the Bahamas totally without the Genset. Didnt work when we arrived - does not work now. A total bust. I know that in our future planning this genset is something we will NEVER trust or rely upon.

Thank God for the Honda Eu2200i gas generator. This lilttle thing has been our salvation and has made keeping going possible. I would never go cruising on any boat without one. THIS thing provides the type of rock solid delivers every time reliability that diesel genset simply cannot touch. I am probably going to purchase another so I can run them together and get all the power I need.

When I am back in the States in a month or so the next step will be to replace the raw water pump with a brand new one and replace the entire raw water feed hose system - every single hose between the thru-hull and the giant main exhaust hose will be replaced. Also I will replace the strainer. When this fails - the giant main exhaust hose and the entire exhaust elbow. If that fails - I will remove this POS from my boat once and for all.

I am without question going to have double the cost in repairing this thing than I would have in purchasing another Honda to run together.

Terry

[more]

Originally Posted by Tspringer

OK -- Wife and daughter flew in and brought the raw water pump rebuild kit.

Kit ordered off ebay - the only one I could get shipped to us in time. This kit came with very poor instructions - parts all numbered on the sheet but no key to the numbers so no way to know what part is really being referenced. I assembled it exactly as the old one came apart.

No matter - rebuilt pump did NOT fix the issue. The amount of water through the exhaust remains the same.

At this point efforts to fix it here in the Bahamas are over. There is no correct 1" diameter exhaust hose in Nassau and no way to get any shipped in time to not lose the families entire vacation. I also cannot source a new strainer here.

So we will complete my season in the Bahamas totally without the Genset. Didnt work when we arrived - does not work now. A total bust. I know that in our future planning this genset is something we will NEVER trust or rely upon.

Thank God for the Honda Eu2200i gas generator. This lilttle thing has been our salvation and has made keeping going possible. I would never go cruising on any boat without one. THIS thing provides the type of rock solid delivers every time reliability that diesel genset simply cannot touch. I am probably going to purchase another so I can run them together and get all the power I need.

When I am back in the States in a month or so the next step will be to replace the raw water pump with a brand new one and replace the entire raw water feed hose system - every single hose between the thru-hull and the giant main exhaust hose will be replaced. Also I will replace the strainer. When this fails - the giant main exhaust hose and the entire exhaust elbow. If that fails - I will remove this POS from my boat once and for all.

I am without question going to have double the cost in repairing this thing than I would have in purchasing another Honda to run together.

Terry

exhaust elbow is a problem.
lifespan on the diesel cast iron exhaust elbow in saltwater is around 5 year

[Uncle Bob]

Originally Posted by more

exhaust elbow is a problem.
lifespan on the diesel cast iron exhaust elbow in saltwater is around 5 year

Given that when checked the pump outflow immediately after the pump approximates the water out the exhaust how on earth could a blocked exhaust elbow create that situation??

[Lodesman]

Originally Posted by Uncle Bob

Given that when checked the pump outflow immediately after the pump approximates the water out the exhaust how on earth could a blocked exhaust elbow create that situation??

Where did you get that idea? - post 23:

Originally Posted by Tspringer

OK - after much wrestling, muscle cramps and cursing I got the raw water hose disconnected from the output side of the anti-siphon. I turned it around to dump in a bucket and fired up the generator.

Water came out of the hose into the bucket significantly faster than has been flowing out the exhaust. So I interpret this as a clogged exhaust elbow.

[Joli]

You have blockage in the elbow of the sea water pump, an impeller blade. It WILL do exactly what you are describing. Take the water pump off and look at the exit of the pump. There is a blade in there restricting the flow, it is very hard to see. Don't ask me how I know.

[Uncle Bob]

Originally Posted by Uncle Bob

Sorry to hear this update, did you ever do the waterpump check where I suggested that you disconnect the pump output and see just how much water it actually pumps when the engine is running? Only needs to run for a very short time but will tell you if the problem is after the pump or before it.
My money would still be on the pump or suction side, it only takes a very small air leak to produce the results you have.

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. I have no reading as such from this from before so I have nothing to really compare it to and no means of really measuring output other than the eyeball. I do agree that the issue has to have something to do with the pump.

at this point I am going to start trying to source a complete pump rebuild kit or an entirely new pump but being in the Bahamas right now I would wager anything they'll not have one in country.

I also think at minimum the strainer needs to be a different type that can be mounted below the water line safely and then I may see about adding a boost pump in line to boost water to the raw water pump or to circumvent it completely. I think that the entire cooling system is extremely marginal and is only effective if everything is an absolute perfect working condition there is no margin for any error.

Originally Posted by Lodesman

Where did you get that idea? - post 23:

That idea probably came from the above post.

[more]

Originally Posted by Uncle Bob

Given that when checked the pump outflow immediately after the pump approximates the water out the exhaust how on earth could a blocked exhaust elbow create that situation??

Simple in exhaust elbow is blocked with a salt crystal.You in big exhaust elbow have small maybe 1x0,5 cm path where raw water flows and mix with exhaust gas.

[Lodesman]

Originally Posted by Uncle Bob

That idea probably came from the above post.

Fair enough - two different answers from the OP. Which is it?

[Tspringer]

Originally Posted by more

Simple in exhaust elbow is blocked with a salt crystal.You in big exhaust elbow have small maybe 1x0,5 cm path where raw water flows and mix with exhaust gas.

True - the water injection fitting is fairly small - a likely place I would think for blockage. BUT - that fitting itself I have checked. Removed the hose - fished long stiff wire tool through it - no indications of any sort of blockage at all.

Now the giant exhaust hose may be delaminated and blocking water flow, I do not know. That is on the list to replace in line with everything else.

[Tspringer]

Originally Posted by Lodesman

Where did you get that idea? - post 23:

What you post is correct - BUT that increased flow did not last!

When I reversed the pump cover and ran the generator - visibly more water did flow out of the exhaust and the generator ran between 4 and 5 hours charging batteries and making hot water. I thought everything was fixed and good to go - pump issue.

Then the next time I ran the genset - having done nothing since the last time when it did run fine - it reverted back to the exact same issue with clearly not enough water out the exhaust and overheating.

Then I completely rebuilt the water pump. Reinstalled and ran genset - NO CHANGE - still not enough water flow. At this same time I triple checked the strainer and coated the lid threads and 0-ring with silicon grease thinking perhaps there was a tiny crack I could not see that was breaking suction.

That is where it is now.

Given the number of suggestions and stories of experiencing this same scenario and finding it due to delaminating 1" ID raw water inlet hose that is what I will try next. I plan to replace all of the hose from the inlet valve to the strainer and then to the genset intake fitting.

Because it seems this type of hose is prone to this type of failure I am considering alternatives.

Why would one not use a 2" section of this hose to attach to solid 1" ID PVC pipe and then using 45 and 90 degree turning pipes route the hose to the strainer and then to the genset intake only using the flexible hose in small pieces to attach to the PVC?

The route the hose takes in my boat would work with this sort of conversion without major modifications. The properly glued together PVC would never come apart and never delaminate. The raw water intake is never hot. This would seem to be a permanent solution?

[gonesail]

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