16 Years, 500 hr and new motor

What you think of a 16 year old boat advertised as only 500 hours on the hull and half of that with a new Cummins 6BT5.9M2? How did they manage to need a new engine at 250 hours?

How do I tell if this is this a cream puff or a red flag?

There's certainly more to the story. Ask.

Greg

Sounds like Nordic Tug, smaller boat with huge horsepower, owner wants to run it a low speed and it can be hard on the engine idling all of the time... I had a friend with a NT 32 and a Cummins, it endlessly gave him trouble because he wanted to idle around at 6 knots and the engine didn't like it.

I think he would have been much happier with 60-100 hp the way he wanted to operate his vessel.

It's not a big deal many times (the act of swapping, not the catastrophic failure). Not the same as a new motor in a car, a ton of things could have happened from a closed raw water seacock to aftercooler issues, to oil leak or ruptured hose to some sort of water ingestion etc. If they can't tell you why it was swapped, then I would be concerned.

I will link you to an article about gas versus diesel, in it you will read that using a motor a little is harder on it than using it constantly. I linked in another thread of a video put out my Mercury in the 1950's of two of their outboards running for 50,000 hours with a mid 25,000 servicing. Of course the purpose of the vid is to show Merc's can take it, but it also illustrates using a motor a lot is less stressful than not using it much at all.

On my now re-powered boat, I was thrilled when the motor only showed 350 hours, how wrong I was, the insides of the motor particularly the heat exchanger were all cruded up.

https://www.yachtsurvey.com/GasDiesel.htm

Sometimes engines just grenade. Even diesels. It's rare, but it's why manufacturers have warranties. I've seen three gas big blocks (different boats, several years apart) do so within their first 3 hours.

Years ago Cat was having an issue with some blocks on their 3116's. Many engines couldn't make it much past 500 hours. Stuff happens.

Shrew,
3 big gas engines “granading” when new is probably because of some mistake, stupidity or negligence in boat building. When I worked at Uniflite an experienced person there said many to most boats experience more use and abuse during construction that later. And Uniflite was considered one of the best boats at the time.

And of course things happen building engines too. Far less probably.

AKDoug said:

Sounds like Nordic Tug, smaller boat with huge horsepower, owner wants to run it a low speed and it can be hard on the engine idling all of the time... I had a friend with a NT 32 and a Cummins, it endlessly gave him trouble because he wanted to idle around at 6 knots and the engine didn't like it.

I think he would have been much happier with 60-100 hp the way he wanted to operate his vessel.

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You Willard owners are always picking on us big horsepowered NT owners.

LOL[emoji16]

Nomad Willy said:

Shrew,
3 big gas engines “granading” when new is probably because of some mistake, stupidity or negligence in boat building.

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I agree. though I've suspected the issue was with engine assembly rather than installation, anything is possible.

Shrew said:

I agree. though I've suspected the issue was with engine assembly rather than installation, anything is possible.

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Mainship replaced several CAT engines in the 390 models because of poor installation. (poor exhaust system design)

I also believe many many more engines die from being run too hard, or being overloaded as opposed to be run too lightly.

But any engine manufacturer can make a bad run of engines due to many reasons.

I would not assume a reason for short engine life.

GregBrannon said:

There's certainly more to the story. Ask.

Greg

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This was the only good recommendation or response. You ask on a forum where none of us have any idea why or what took place or the history or condition of the boat.

BandB said:

This was the only good recommendation or response. You ask on a forum where none of us have any idea why or what took place or the history or condition of the boat.

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Close the thread, the almighty has spoken. Only one good response here.

rsn48 said:

I

On my now re-powered boat, I was thrilled when the motor only showed 350 hours, how wrong I was, the insides of the motor particularly the heat exchanger were all cruded up.

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The highlighted bit is surely lack of maintenance not lack of use.
Easy fix none the less.

We looked at a Bayliner 4788 that had Cummins engines in it. The boat was a 2000, I think. When I looked in the engine room I was amazed how nice looking the engines were. I asked the broker about them and he said that Cummins had replaced the engines about 3 or 4 years earlier. He said the PO of the boat knew someone at Cummins and got them to replace the engines for some reason. The really strange thing was there was no mention in the listing about new engines and the broker never mentioned them until I asked. You would think that this would have been the first thing in the listing and the first thing that the broker would be talking about.

GregBrannon said:

There's certainly more to the story. Ask.
Greg

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Gets difficult if the current owner was not at time of replacement. But you are on notice something happened

Recently a newish Beneteau ST sold here with new engines, and a Riv on my marina had both engines replaced after insurance total loss. Both were water entry related.

GregBrannon said:

There's certainly more to the story. Ask.

Greg

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Of course, and how completely the question is answered will go far toward weighing your confidence in the seller. Every boat has a story - or lots of stories. Beyond a certain point, it matters more how a boat was maintained than how it was built. Those are the stories you want to hear, preferably right from the owner.

8 year old Cummins with 200 hours. What do you think would happen it someone decided to bring it up to 80% power?

Arc said:

View attachment 96915



8 year old Cummins with 200 hours. What do you think would happen it someone decided to bring it up to 80% power?

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I assume nothing good- but help me out what are we looking at ? A clogged aftercooler? What would cause this?

AKDoug said:

Sounds like Nordic Tug, smaller boat with huge horsepower, owner wants to run it a low speed and it can be hard on the engine idling all of the time... I had a friend with a NT 32 and a Cummins, it endlessly gave him trouble because he wanted to idle around at 6 knots and the engine didn't like it.

I think he would have been much happier with 60-100 hp the way he wanted to operate his vessel.

Click to expand...

Hi, my questions to cummins:

Hi,

I have a Cummins 5.9 qsb marine engine 2009 and it reaches max rmp 3065 which is perfect my Nordic Tug 37.

I have read a lot of conflicting opinions on the engine to run at low rmp a long time, because the machine may damage the carbon and etc. Some say it's ok to run this type engine at low rmp if the coolant remains in the correct slot.

The time i run my engine is most often 850-1300 rpm since the boat is most economical in this rmp area and temperature is ok. Cummins runs fine and does not smoke any, exhaust pipe mouth environment does not show any black carbon.

What is the manufacturer's view of low load low rmp almost always, whether it is ok or damaging the engine?

It would be great to have an expert answer, all the web instead of rumors.

xxxx


Cummins say:

Xxx
This is fine for our engines. It is not suggested to Idle (650-750rpm) for long periods. Generally speaking, you can idle for about 20 minutes or so at this range and be okay. If you plan to idle longer than 20 minutes or so it is suggested that you ramp up your RPM to about 800-1000. Working the engine under a light load/rpm is fine. This is not uncommon for some our engines (like Generators which normally work at 1800 RPM or less) and will not cause any undue harm.
Thank you for contacting Cummins.

Xxxxxx


Customer Care Representative
If we have misunderstood the information in your communication or you have additional questions please feel free to respond to our support staff by e-mailing support.engineparts@cummins.com or 1-866-CUMMINS (286-6467). If you are located outside of North America, you can reach us at 1-615-871-5500.

NBs

16 year old with 500 hours ? I would be more concerned with "when" the engine was changed. Was it 15 years ago as a warranty thing or was it last year ? Lots of times boats can sit for years then a new owner, or son, or daughter ends up with it and runs the hell out of it for a year or more so you can't assume that for the past 16 years the boat was used 30 hours a year.

pete

Pete Meisinger said:

16 year old with 500 hours ? I would be more concerned with "when" the engine was changed. Was it 15 years ago as a warranty thing or was it last year ? Lots of times boats can sit for years then a new owner, or son, or daughter ends up with it and runs the hell out of it for a year or more so you can't assume that for the past 16 years the boat was used 30 hours a year.

pete

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Right, never assume. Our boat when purchased had 2050 hours at 32 years old. I emailed the factory to confirm it was the original engine. So that's about 65 hrs a year. And it too has a higher hp motor for the size boat. We ran it mostly at 1000 to 1150 rpm for the 1700 mile. But it was sure nice to have 300 hp when going into a inlet with a following sea.

Comodave said:

We looked at a Bayliner 4788 that had Cummins engines in it. The boat was a 2000, I think. When I looked in the engine room I was amazed how nice looking the engines were. I asked the broker about them and he said that Cummins had replaced the engines about 3 or 4 years earlier. He said the PO of the boat knew someone at Cummins and got them to replace the engines for some reason. The really strange thing was there was no mention in the listing about new engines and the broker never mentioned them until I asked. You would think that this would have been the first thing in the listing and the first thing that the broker would be talking about.

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The Bayliner 4788 is a great boat that was overpropped for real life load out on the boat.

Mine needed new engines at just 900 hours due to overpropping. The Cummins 6BTA engine is a great engine but it does not like being overpropped.

As far as the OP’s question, yes simply ask what happened to the original engine. Unless the need for replacement is a uncorrected latent defect then the new engine is a blessing.

I bought my boat knowing it needed to be repowered. That way I got a boat with two brand new engines that I could take care of properly.

You need the log book. If there is one.
That will tell you how many hours a year, over the life of the log book.
I have 3 separate sets of hour meters. Every time I get a survey, the surveyor notes the hours from a different set of meters.
One is disconnected, just sit there so I don't have to fill the holes they are in. They show the # of hours from my purchase of the meters to changing engines, approx 1100 hrs on both.
Second is up top. Show the hours since I bought a second pair of tachometers for my replacement engines, Each was used, so have random hours, plus what has been added.
Third is on the tachometers in the main engine panels. One shows accurately what is on that engine, as it has been with that engine since new, though on a different boat for its first 1500 hrs. The other also shows what was on that engine when I bought it, again 1500 hrs, plus what was added before its subsequent rebuild, plus what has been put on after that rebuild. My log shows the # of hours at that rebuild, so to get an accurate #, you need to read the log and subtract that number from the display.
The OP's 500 could be as complicated or worse.

murofrelwart said:

I assume nothing good- but help me out what are we looking at ? A clogged aftercooler? What would cause this?

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Don’t you guys know anything? Those are the alien egg cases. One looks like it already popped out into the POs face!

Cummins

There was an issue with A very small run of 6 cyl. Block castings. they were used in Ram trucks. If any of them were used in marine applications this may be why it was changed. The blocks cracked along the side due to a thin water jacket.

Off thread but boat brokers < used car salesmen

Comodave said:

We looked at a Bayliner 4788 that had Cummins engines in it. The boat was a 2000, I think. When I looked in the engine room I was amazed how nice looking the engines were. I asked the broker about them and he said that Cummins had replaced the engines about 3 or 4 years earlier. He said the PO of the boat knew someone at Cummins and got them to replace the engines for some reason. The really strange thing was there was no mention in the listing about new engines and the broker never mentioned them until I asked. You would think that this would have been the first thing in the listing and the first thing that the broker would be talking about.

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I have met a few good ones but in working on lots of boats I've come across and heard about more shifty ones.

BandB said:

This was the only good recommendation or response. You ask on a forum where none of us have any idea why or what took place or the history or condition of the boat.

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Seriously??? (insert head scratch here)

Here's the OP:

AdkChris said:

What you think of a 16 year old boat advertised as only 500 hours on the hull and half of that with a new Cummins 6BT5.9M2? How did they manage to need a new engine at 250 hours?

How do I tell if this is this a cream puff or a red flag?

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No helpful suggestions at all? Just judgmental and condescending remarks? Did you get up on the wrong side of the bed today?

AdkChris, first off, Welcome to TF!! Lots of folks with differing opinions and experience here. I hope you find the lion's share of the replies helpful.

Any 16 year old boat listed with 500 hrs would be a red flag to me. That same boat with a new engine installed 250 hrs and unknown years ago is another red flag to me. A boat like this with no maintenance logs would be another red flag to me. (Not sure if you have access to mx logs.)

Take our help (and criticism) with a grain of salt but always do your due diligence. Take nothing for granted. It can be a long hunt for that "just right" boat but, in the end, it's worth doing it right.

Happy Hunting and please keep us updated.

Cheers!

I wouldn’t worry too much about the previous engine. Spend your time and money doing a survey of the current engine.

More info pls

Arc said:

View attachment 96915

8 year old Cummins with 200 hours. What do you think would happen it someone decided to bring it up to 80% power?

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What are we looking at here?

Tom T said:

What are we looking at here?

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That's the bottom of a Cummins aftercooler clogged with marine growth. The cap has been removed to expose the core.

This is the way it should look when cleaned and serviced. Image is from Seaboard Marine.



And here is where Seaboard fully covers the Cummins Aftercooler Maintenance.

Follow Tony's procedure to the letter and you'll get long service life from them. Ignore it at your peril. Typical service interval is about two years.