Sheen/Sooting from my 7.6BTD - troubleshooting advice?

Updating this. I got back from the 4 day weekend, we ran the generator quite a bit (it was hot weather, so we ran the AC a lot) and I did indeed see a sheen on the water when I was running it. I also had some sooting on anything that was in the water - lines, floats, etc. I'm pretty sure that it is, as Mark indicated above, the exhaust elbow. Without confirming that yet, I'm inclined to buy the kit from Westerbeke and replace the entire assembly since I'm sure it's original, and that would allow a straight swap right away and not have to deal with finding a place to get it cleaned before I leave for my big trip in 2 weeks.

I just wanted to confirm that this is what I'm looking at (I think it is based on pics from David's post above):
Parts manual:
Exhaust Elbow.png

Westerbeke kit (it's just over $100):
Exhaust Elbow Kit.png

Does that look right? If I pull it off and it's not clogged, I'll deal with that, but I think given the info I got from this thread, it's going to be pretty likely.
 
There are 2 versions im aware of…a 45 and 90 degree. Might want to look at your genny and confirm. Mine is the 45.

the other part of this is the exhaust manifold…it got coolant running through it, and on mine I suspect a build up of diesel soot as the exhaust gases hit the much cooler manifold.

Both could be an issue. Manifold is expensive, and mine had pitting on the sealing face requiring a new gasket, and some RTV to seal as a temp fix till this winter.

I also suspect resetting the head (injector timing) and or having the injectors tested/cleaned would help…too much fuel or bad spray pattern could also produce this…it’s basically partially/unburned fuel.
 
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Updating this. I got back from the 4 day weekend, we ran the generator quite a bit (it was hot weather, so we ran the AC a lot) and I did indeed see a sheen on the water when I was running it. I also had some sooting on anything that was in the water - lines, floats, etc. I'm pretty sure that it is, as Mark indicated above, the exhaust elbow. Without confirming that yet, I'm inclined to buy the kit from Westerbeke and replace the entire assembly since I'm sure it's original, and that would allow a straight swap right away and not have to deal with finding a place to get it cleaned before I leave for my big trip in 2 weeks.

I just wanted to confirm that this is what I'm looking at (I think it is based on pics from David's post above):
Parts manual:
View attachment 131774

Westerbeke kit (it's just over $100):
View attachment 131773

Does that look right? If I pull it off and it's not clogged, I'll deal with that, but I think given the info I got from this thread, it's going to be pretty likely.

My part # 37402 which is the 45°
 
There are 2 versions im aware of…a 45 and 90 degree. Might want to look at your genny and confirm. Mine is the 45.

the other part of this is the exhaust manifold…it got coolant running through it, and on mine I suspect a build up of diesel soot as the exhaust gases hit the much cooler manifold.

Both could be an issue. Manifold is expensive, and mine had pitting on the sealing face requiring a new gasket, and some RTV to seal as a temp fix till this winter.

I also suspect resetting the head (injector timing) and or having the injectors tested/cleaned would help…too much fuel or bad spray pattern could also produce this…it’s basically partially/unburned fuel.

I might pull ours out this winter and send them to have tested/cleaned. Anyone have any advice on who would do this?

also as an aside but somewhat related. I think I'm going to pull the trigger on a custom sound cover from GSI in ft. lauderdale. They're not cheap but I spoke with the owner a bit and it sounds like it will do amazing things for quieting the gen down.
 
Any old-school radiator shop...


I think he means the injectors……….

The actual test should be done by a diesel specialty shop that has test equipment for injectors and pumps which is usually a clean room environment. I pulled my westerbeke injectors and had them pop tested every 500 hours. This is a test where the injector is mounted on a test stand and pumped up with a solvent to fire the injector so the technician can evaluate the spray pattern and the point at which the injector sprays fuel. These as very simple mechanical injectors so the test stand gives the technicianl the opening and closing pressures and lets him visually evaluate the spray pattern.

Westerbeke recommends resetting the valves and re-torquing the cylinder head at 500 hours so you probably should have that service done or do it at the same time you pop-test the injectors.

I had an 8.0 BTD which is a 3 cylinder diesel. Every time I had the injectors pop-tested, they found one injector that was carbon fouled on the tip…….the engine was running perfectly, just a little valve clatter and louder than normal diesel knock. The solvent used for the pop-test cleaned the carbon from the injector tips so in 25 years of ownership, SAE 40 RetellaT1, every 100 hours, never overheated, new water pump every 300 hour, reset the valves and retorqued the cylinder head every 500 hours ….i.e. text book maintenance.
The cost for the set up and pop-testing the injectors was $75 ………I pulled the injectors out, retorqued the head and reset the valves and UPS'd the injectors to a diesel specialty shop 90 mile away in Pensacola FL. The diesel shop included new injector cups as a part of their service. This was all my 1700 hour Westerbeke ever needed.

Pulling the injectors isn't a big or time consuming job…..unlike resetting the overheads on a 3116/3126 which is about an 8 hour job. Even if you don't want to pull the injectors and reset the valves or retorque the head, removing and replacing the injectors is pulling the injectors about 1.5 hours…..and you only need to do it every 500 hours.


Frank
 
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I think he means the injectors……….

The actual test should be done by a diesel specialty shop that has test equipment for injectors and pumps which is usually a clean room environment. I pulled my westerbeke injectors and had them pop tested every 500 hours. This is a test where the injector is mounted on a test stand and pumped up with a solvent to fire the injector so the technician can evaluate the spray pattern and the point at which the injector sprays fuel. These as very simple mechanical injectors so the test stand gives the technicianl the opening and closing pressures and lets him visually evaluate the spray pattern.

Westerbeke recommends resetting the valves and re-torquing the cylinder head at 500 hours so you probably should have that service done or do it at the same time you pop-test the injectors.

I had an 8.0 BTD which is a 3 cylinder diesel. Every time I had the injectors pop-tested, they found one injector that was carbon fouled on the tip…….the engine was running perfectly, just a little valve clatter and louder than normal diesel knock. The solvent used for the pop-test cleaned the carbon from the injector tips so in 25 years of ownership, SAE 40 RetellaT1, every 100 hours, never overheated, new water pump every 300 hour, reset the valves and retorqued the cylinder head every 500 hours ….i.e. text book maintenance.
The cost for the set up and pop-testing the injectors was $75 ………I pulled the injectors out, retorqued the head and reset the valves and UPS'd the injectors to a diesel specialty shop 90 mile away in Pensacola FL. The diesel shop included new injector cups as a part of their service. This was all my 1700 hour Westerbeke ever needed.

Pulling the injectors isn't a big or time consuming job…..unlike resetting the overheads on a 3116/3126 which is about an 8 hour job. Even if you don't want to pull the injectors and reset the valves or retorque the head, removing and replacing the injectors is pulling the injectors about 1.5 hours…..and you only need to do it every 500 hours.


Frank

Perfect, and yes sorry - responded in haste and I should have been clear I’m planning on pulling the injectors. I’ll likely pull the mixing below as well but we’re fresh water and it only has 150 hours on it so we’ll see what I find (at $100 I might just swap it, though)

I see all the maintenance steps outlined nicely in the Westerbeke manual and nothing seems overly complex. Given the severe under-use our genset has its due for all baseline maintenance items
 
I have one similar to this one.... soft-sided with velcro to hold it together. It was on the boat when we bought it so I don't have anything to compare it to, but I think our gen is pretty quiet. http://www.marineinsulation.net/custom-soft-sound-shields/
I've had the pattern for a while, just other jobs have taken priority.

I recently pulled the info back out and started contemplating how to work around the fuel lines, exhaust and electrical, and how to mount it.

I have several things that need to be done as the guy I thought was going to torque and set the head, and pull the injectors ghosted me, so still needs to be done, but this is finally high priority this winter.
 
I recently pulled the info back out and started contemplating how to work around the fuel lines, exhaust and electrical, and how to mount it.

For lack of a better term "frillies" or tassels. The vinyl material is shredded in areas where access is needed. The air intake is more like a scoop.
 
I see all the maintenance steps outlined nicely in the Westerbeke manual and nothing seems overly complex. Given the severe under-use our genset has its due for all baseline maintenance items
Did you find that on the Westerbeke site? I'd like to check to see if it's in my skill set to do.
 
Perfect, and yes sorry - responded in haste and I should have been clear I’m planning on pulling the injectors. I’ll likely pull the mixing below as well but we’re fresh water and it only has 150 hours on it so we’ll see what I find (at $100 I might just swap it, though)

I see all the maintenance steps outlined nicely in the Westerbeke manual and nothing seems overly complex. Given the severe under-use our genset has its due for all baseline maintenance items
Your system will fail sooner from under use then over use...
 
Bumping this one back up. I never did pull the injectors, I actually tried one time to get the fuel lines off but they were stuck pretty well and the hard lines were starting to flex a bit too much for my comfort and I didn't want to bend/kink/put a hole in them, so I backed off. After that, we didn't do any boating last summer due to health reasons. I'm now looking to get this done before spring, so I'm looking for advice on how to remove the injectors.

My plan is to just soak the attachments with penetrating oil and give it a go. It seems like it should be straight forward, is it though?
 
Bumping this one back up. I never did pull the injectors, I actually tried one time to get the fuel lines off but they were stuck pretty well and the hard lines were starting to flex a bit too much for my comfort and I didn't want to bend/kink/put a hole in them, so I backed off. After that, we didn't do any boating last summer due to health reasons. I'm now looking to get this done before spring, so I'm looking for advice on how to remove the injectors.

My plan is to just soak the attachments with penetrating oil and give it a go. It seems like it should be straight forward, is it though?
I just don't know how the injectors on a mechanical injection engine can contribute to fuel on the water and excessive soot. There are several things that can over fuel these little engines, all related to the injector pump - injector pump is out of calibration, something failed, and/or injector pump timing. The injector pumps are a variable positive displacement pump that is gear driven. There is a centrifugal govenor that controls the fueling inside of the housing.
 
My 8.0 BTD started sooting a few years back, it turned out to be the exhaust mixing elbow. It was over 50% clogged with soot and needed to be replaced.
 
My 8.0 BTD started sooting a few years back, it turned out to be the exhaust mixing elbow. It was over 50% clogged with soot and needed to be replaced.
I replaced that earlier, it wasn't too bad, but it definitely didn't help with the sooting/sheen.

I just don't know how the injectors on a mechanical injection engine can contribute to fuel on the water and excessive soot. There are several things that can over fuel these little engines, all related to the injector pump - injector pump is out of calibration, something failed, and/or injector pump timing. The injector pumps are a variable positive displacement pump that is gear driven. There is a centrifugal govenor that controls the fueling inside of the housing.
Frank indicated earlier that injector cleaning is a routine maintenance item, and I've not done that yet, so I was thinking that if they are fouled, it could contribute to what I'm seeing. It's also supposed to be a fairly easy thing to do, so I would try that next. I'll look into the injector pump idea and see if there's anything to that.
 

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