[Gary Marshall]

Thanks. It is good to have that specific knowledge just in case he needs to get the pump done. 

As mentioned, it’s Barbados, so there are not a huge lot of options in terms of shops that do this sort of thing. Don’t know too much about this particular person. Good to know that the price is fair. Labour tends to be cheaper here, relative to the US, whereas imported parts would cost quite a bit more. 

He did go fishing yesterday for 10 hours or so, and didn’t mention any issues on it yesterday evening (I had forgotten to ask about it)

Thanks all.

 

[Gary Marshall]

I asked him for an update yesterday and he said the issue reoccured twice since then, but to a lesser extent. It did clearly make a big difference, but it might still not be 100% resolved.

He got a local quote for USD $750 to rebuilt the pump, but the person also wants to clean the injectors also. Might all seem logical, but keep in mind that these injectors were all cleaned recently while the engine was rebuilt, and this is a “new” rebuilt fuel pump he is using. So, he will continue to see how it goes for now. He is a commercial fisherman so the boat gets practically daily use.

G.

[Gary Marshall]

Guess what?!? This solution seems to have worked. My buddy tried it at first a bit, and it didnt’ seem to make a difference. Then he took the boat around to the other side of our island (Barbados) to a sheltered port, and added more ATF (I think filled the racor with it), and the problem resolved. He has used the boat a bit since and the problem has not re-occured. So, fingers crossed I guess. Thanks again!

[Gary Marshall]

There is no local dealer support for Cummins or John Deere in Barbados. However, there is a John Deere dealer in Grenada that provides John Deere’s for Barbados. Cummins is also a popular brand here, but again, no local dealer support. John Deere is probably the easier local option, but Cummins has the “Tony Athens” advantage, where I can turn to this forum for help.

I am still weighing options. One option is a locally built boat in which I have the choice of option. Or, there are a couple old boats I am looking at, which might need a repower. I’m not really considering a North American built boat at this time for this application. 

[Gary Marshall]

Hi all –

Long post warning… 🙂

Just wanted to document what modifications I have done so far with my exhaust. I am a novice, and learning, so critical comments are welcome.

I removed the exhaust elbows off the engine and inspected the turbo. It looked similar to my previous inspection in late 2017, with some rust present, but the flan blades and such still looked in good shape. Of more concern was the unevenness where the elbow bolts onto. I did my best with the orbital sander, wire brush and hand file to remove all exterior rust, apply an ospho rust treatment, and paint the exterior with a high temp 2000 F paint, and ensure the mating surface was level. I bolted back on the two elbows with new v-clamp and metal gaskets (it’s a real pain to ensure the gasket is in position before tightening down, with the limited access). I had removed some 2” insulation above the mixing elbow so I was able to rotate it slightly more, and raise it slightly. <br /><br />I replace the 4” exhaust hose with a new one, as the old one had a noticeable bulge in one area, and I have not replaced it since I owned the boat in 2017.

The Centek muffler I removed, and added a 1” Groco thru hull which I glassed in with a mix of csm/woven mat, using epoxy resin. A 1” hose attaches to this, and runs down to the bilge, with a Groco bronze valve on the end, which is easily accessible from a hatch in the cabin (behind the steps). Unfortunately this muffler is under the water line, so exhaust water always remains in it, and I wanted a way to remove all exhaust water from the system.

I would have liked to put in a surge tube between this Centek muffler and the engine elbow, but the room/height I don’t think would have allowed for an effective design, as the existing slope from the exhaust elbow I did not want to make any more gradual.

Now, as the Centek muffler is below the water line, I made a goose neck using Centek 5” fiberglass tubing from Defender.com. I cut the angles using a miter saw & angle grinder (as the miter saw blade was not large enough). I generally made 15 degree angle cuts, so the angle was more gradual heading up the goose neck, with a steeper downhill run before exiting the boat on the port side. I raised the gooseneck to just below the floor, which was the maximum I could easily do it, still trying to ideally keep it slightly lower than the exhaust on the engine, for a safety margin.

Now, the boat has launched, and all had worked well, except for the following flaws.

When the boat is light, the top of the gooseneck is above the water line comfortably. However, when the boat is fully loaded with ice and fuel, water sloshes over the gooseneck whenever the boat rolls. This is very dangerous as the valve needs to be open whenever the engine is off, and the bilge pumps/float switches need to be working well. Otherwise if the valve is off, the centek muffler is likely to fill and water rise in the exhaust system, to the level of the gooseneck/exhaust elbow, and the engine will drink some more saltwater.

As a temporary measure, we are opening the new muffler valve, and plugging the exhaust with a foam buoy shaped to fit the internal 5” fiberglass elbow to reduce water entry.

As a longer term measure, I plan to either raise the height of the goose neck by seeing if it can fit inside the “wall” of the boat side. I might take Tony’s suggestion in another post and utilize a square section for the exhaust here, to ensure I keep at least the same surface area as the 5” tubing, as I don’t think the 5” tubing itself will fit here). If I have space for this to work, the only issue would be that the height of the gooseneck will be above the height of the engine elbow, so I risk flooding the engine if the valve is closed, and there is excess sea water in the system (either from entering over the raised elbow, or from cranking the engine excessively if it has a starting issue)<br />Or, keep the existing goose neck, but rather than route the exhaust out the side of the boat, I have enough room in the transom at the port side to bring it up and out the boat, above the swim platform, well above the water line. I assume the exhaust might be a little louder here as it wouldn’t be exiting in the water, but for sure, water should not be able to enter the exhaust via the exit, and even if it did, the goose neck would add significant protection, and I would still likely open the valve to drain water in the system.<br /><br />Happy to hear any criticism, thoughts, suggestions….

 

[Gary Marshall]

Right now the exhaust exits out the side of the boat, but close to the transom. I’m not sure that having a shorter run, if it doesn’t utilize any more height, can help the backflow situation.

I have a couple ideas working with, which I will share, just didn’t get chance to do any work on it this last weekend.

[Gary Marshall]

Am still considering my options. I’m in Barbados, so the shipping costs is something to consider also.

If the pipe won’t cut off, could just cut it off and glass over also. But right now am thinking of just getting something premade as it looks to be sometime before we get back quality resin in the island.

[Gary Marshall]

Thanks Alex & Tony –

Good idea about the possibility of using square section rather than round, to help ensure backpressure stays within bounds.

I got the boat hauled yesterday, so will take a better look this weekend at what my options are.

[Gary Marshall]

I will check out your post.

I’m hauling the boat tomorrow, so once it is up I will start to formulate my plans.

It seems many local boats use lots of Sch 40 PVC as their exhaust. Or, at most, fiberglass over some pvc tubing. I am pretty skeptical of that approach. But making the fiberglass pipe is probably a lot more cost effective than importing it.

[Gary Marshall]

Sounds like the manufacturer exhaust pressure specs are normally relatively conservative, if I am reading you right.

How would one know if the engine had too much back pressure? What symptoms might it exhibit?

I’m definitely thinking about making my own fiberglass tubing, but with supply/demand challenges globally right now, the local suppliers are out of just about everything! But I’m waiting to hear if it will be weeks or months before they get back in stock.

[Gary Marshall]

Thanks Tony. While I read all these articles a few years back, they seem a lot clearer to me now with the benefit of a bit of experience.

I understand better now, so it looks like what you have labelled as the “muffler dip tube” should extend down fairly close to to the bottom of the lift muffler, say 3 or 4 inches off the bottom, and the water level would stay in line with the bottom of the muffler dip tube when engine is on.

Does adding a lift muffler of this nature to an exhaust system generally add a lot of back pressure? (it’s a yanmar 6lpa I have installed)

I don’t have the gauges and fittings to measure back pressure, so I am just hoping to not to increase it by too much. Also was reading your tips about possibly reducing back pressure by diverting some of the exhaust water out of the boat before it enters the mixing elbow (not sure if you have any such inline fittings to add, I suppose about a 3/4″ hose or so).
I suppose reducing the waterflow out of the exhaust might reduce back pressure a bit, but if too much is reduced, the temperature of the exhaust might increase. A lot of variables to study for a person who didn’t have a clue about this stuff a couple of years back!

[Gary Marshall]

Picture on the article I am referring to.

[Gary Marshall]

Thanks, but not sure what you are referring to here. I had posted a lot of pics in the first few posts, I think on page 1.

[Gary Marshall]

That doesn’t look too pretty!

I changed my yanmar cast iron mixer and riser elbow to cast 316 replacement versions back in late 2017, so I am thinking I should be good there.

My captain brought the boat back around from the port where it was in Bridgetown to Consett Bay where we fish from (other side of the island) this morning. The engine sounded fine, and no more issues with water in the oil so far, so all indications still point to water from the exhaust.

However, we did have an oil leak with oil pooling on the side of the valve cover. I believe it is coming from where the diesel lines enter the cover, there is like a rubber boot around the lines. The rubber boot is more visible on the inside of the valve covert though. Looks like a couple of them are leaking.

[Gary Marshall]

Thanks! I have been pouring through Tony’s articles (not for the first time) and some things which were not as clear to me initially I think I am understanding a bit better now.

So the surge tube basically is an inline pipe in the exhaust, which will normally drain of water, but if a wave or rock of the boat causes water for some reason to come back up the exhaust, it will fill that “dummy” end of the “Y” before it is able to go back up the exhaust hose to the engine. I like it. I will see what room I have, and what might work in my application. I think I might prefer a larger or longer dummy section. Maybe add a piece of dummy hose there which is capped, running under the actual exhaust hose. Might provide more security in heavy seas with engine off, or if on hauling up the operator lifts the stern of the boat before the bow.

[Gary Marshall]

Thanks for that reply.

I had not heard of the “Y-piece anti-reversion tube” before. I will have to do some research on it, looks like some sort of internal “flapper” one would put just after the mixer elbow, or perhaps further down the line.

Seems like some of the local commercial boats have put some sort of “water lock” in the system with a drain. Basically a fiberglass container, at some point in the exhaust, which has a drain that you can open when you turn off the engine. Any seawater in the system will drain into the bilge. You just need to remember to close the drain, or turn back the valve before you start the engine. I do want to ensure whatever i do is “fail-safe”. And regardless of the system, it won’t introduce much additional “back pressure” (that I know little about, other than reading on sbmar).

We got the engine started back yesterday evening, and the plan is to use it for about an hour today, and then change the oil again. It started easily so hopefully that is all a good sign.

[Gary Marshall]

Hi all,
I’m trying to understand why this would have happened and how I can stop it from happening again.

The engine has on 8,700 hours, 8000 of which we have put on since we bought the boat in Jan 2017.
My boat was on a 4 day commercial fishing trip. My captain went to start the boat on Thursday morning to head home, and just heard “clunk”, as the starting motor would not turn the motor. We had assumed starting motor issues, as while it had never given trouble we were planning to get it serviced soon. I got the boat towed back to shore that day and offloaded the catch on Friday. The mechanic was a no-show on Saturday, and on Sunday I just decided to check the oil (which had just been changed before this trip) and realized it was about an inch and a half above the maximum mark on the dip stick. I then tried turning the engine using a socket on the flywheel and could not get it to budge. I got the oil pump, and pumped the oil up through the dipstick connection to check it, and at least a gallon of clear salt water came out first, before oil started to come.
Note that my coolant levels were fine, and my coolant is a bright orange colour. Definitely was not coolant in the oil.

Unfortunately my mechanic was a no-show again on Sunday. I removed the valve cover, but quickly realized that removing the injectors was beyond my limited knowledge. I arranged for a different mechanic to come on Monday (yesterday) and using a 6mm threaded rod devised as a slide hammer, he was able to remove the injectors, after removing the fuel return line. After squirting some penetrating lubricant down the injector holes, we were able to turn the engine by hand. Water hit the roof of the cabin from the pistons pushing the water out of the cylinders. We then cranked the engine briefly using the starting motor (with seacock closed) to clear out the remainder of the water. We then stopped for the evening due to fading light, after putting some more rust inhibitor lubricant in the injector holes.

I believe he will use diesel to flush the engine today, followed by an oil change or two. But any advice /suggestions here is appreciated.

Now, the main possibilities seem to be either relating to the oil cooler, or maybe an issue with the exhaust mixing elbow, or seawater back up the exhaust into the turbo, and then engine.

The engine has been working flawlessly without issue, and this trip was no different. My captain is also excellent in terms of picking up a change in engine noise. He would have run the engine for about 16 hours that day before switching off the night about 9 pm, and drifted till 4 am the morning when he went to start back up and have the issue. The sea did get rough overnight (but he has operated in plenty of rough conditions before also over the last ~ 5 years).

I would think that if it was the oil cooler, it would have had to occur while the engine was running, and he would have likely noticed some change in the engine noise. He would have idled for about 3 hours after dark, so may not have noticed any change to exhaust gases/smoke. I’m not sure what would be expected here, but I don’t think the engine would have liked a gallon of water in the sump, and cylinders full of water. I’m also not sure the cylinders could easily get full of water in this manner, via the engine running. So I am doubtful of this.

In relation to the exhaust. I changed the stock cast iron yanmar exhaust riser and mixing elbow with stainless steel replacements from HDI Marine back in 2017. (https://hdimarine.net/product/hot-1-stainless-steel-exhaust-riser/ ). I had taken pics of the exhaust at the time and Tony advised that sea water appeared to have gotten to it at some point in time. In installing the new riser/mixing elbow, I rotated them slightly more, to get about an inch more height (before butting with the floor of the boat). Again, I have not had any sort of issue with water in the oil since that time.

I will also mention that occasionally this year while the boat has been on the open ocean drifting, my captain has had a “hard start” where he has to crank the engine slightly longer than normal. Normally the engine starts very easily, and never gives trouble starting at the mooring. He put this down to the boat listing slightly on one side while drifting, and thinking it was fuel related. I’m not sure I agree with this, but it does not happen very often. Note that the boat is also very loaded up with ice, fuel and so on for these fishing trips, so sits a little lower in the water.

My expectation is that sea water coming back through the exhaust is the culprit, and even though I have never seen sea water in the sump before on doing an oil change, or noticed the oil level being high, perhaps it didn’t happen in this quantity, and was the reason for the occasional hard start in the ocean.

If this is the issue, what options do I have? I can’t get the exhaust any higher, and the rubber hose that fits onto this runs at a decline from the engine, to the port side of the boat, then into a large fiberglass pipe running down the port side to the stern, exiting at the water level on the port side at the stern. I have no flapper valves. We used to stick a buoy in the exhaust hole when drifting but it used to come out easily, and at any rate, water would be in the fiberglass exhaust pipe anyway, so it might help with a “wave” but not with water coming up the exhaust due to an extended roll of the boat in heavy seas. I saw some suggestion of using a valve in the exhaust, but even if I could install one suitably, it would seem that was an accident waiting to happen, as forget it shut once, and you would have a major issue.
Sorry for the long post, but wanted to give as clear a picture as possible.

I have lots of pictures in my earlier posts above. Thanks for any help or suggestions.

[Gary Marshall]

A bit late on my response. I have a 6LPA-STP with 7200 hours (6500 hours put on in the last 3 to 4 years). I imagine the service is very similar.

In my annual haul up I have my mechanic do the valve adjustment, and we change the timing belt (we put on about 2,000 hours per year). The timing belt always looks great, but not about to chance it. I do have good access in front of my engine to change it however.

I did change my elbows to the HDI Marine ones, back in 2017, and they have been perfect so far.

I am trying to deal with some rusty areas around the transmission and one engine mount right now. I am treating mine with the wire brush, some ospho, and I would normally use “cold-galv” spraypaint but can’t find any, so prob brush on some red-oxide.

I do the normal service items as you have listed, and keep track of them in a spreadsheet per the attached.
There is a product locally called SA342 but it is sulphonic acid/sulfonic acid used to clean lime in boilers and so on. I run it through my cooling system for a few hours using a little portable rule bilge pump in a pair of old gloves as a “stainer”. Then flush with water. figure it can’t hurt. Obviously not as good as bench cleaning and testing the million heat exchangers on the engine, but access is very poor to get some of them out.

I now looked at your pictures. Wow….can you cut an access hole in front of each engine to do the timing belts?

[Gary Marshall]

This might be a little late, but perhaps still help someone.

I use Prestone Extended Life Coolant. It is orange in colour.I get it easily here in Barbados, so would imagine it is readily available where you are.

I have a 2005 6LPA-STP in an Albin 28, with 7200 hours. I put on about 2,000 hours a year, and change it on my annual haul up when we change the timing belt.

[Gary Marshall]

Thanks Rob. I don’t post much these days, but enjoy reading your helpful responses whether on sbmar or over on the albin forum. It’s appreciated!

Not being too familiar with the connector, didn’t realize it had a spring tension in it.

I will email Russel for both.

G.

[Author]

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