Cummins - Yanmar

Albert Jr.

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Curacao
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Boston Whaler, Alliance and other random brands
I've noticed while looking at lobster boat plans that people use the Yanmar
engine more often in their plans.
I've also noticed the same in articles about repowering.
I thought Cummins was the preferred engine.

What is the reason for this ?
 

jwalka51

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Newport R.I.
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26' Webber Cove lobster boat.
when you say lobster boat do you mean an actual working commercial lobster boat??? Or just a downeast style boat??? If you are talking actual about lobster boats then you are mistaken with the yanmar Idea. Yanmar is not a commercial grade engine. They are actually garbage in my opinion. In actual commercial boats, you will see alot of cummins though, as well as caterpiller, john deere, lugger, isuzu, detroits and volvos. I have seen very few commercial boats with yanmars if any.
 

Albert Jr.

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when you say lobster boat do you mean an actual working commercial lobster boat??? Or just a downeast style boat??? If you are talking actual about lobster boats then you are mistaken with the yanmar Idea. Yanmar is not a commercial grade engine. They are actually garbage in my opinion. In actual commercial boats, you will see alot of cummins though, as well as caterpiller, john deere, lugger, isuzu, detroits and volvos. I have seen very few commercial boats with yanmars if any.

I don't like the Yanmar brand either.
It's the downeast style boats that I'm talking about.
 

hntrss

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They are very small footprints. Therefore they fit under deck much better than the competition. This makes them popular in the small, recreational DE boat market. Truthfully, I feel like they were kind of a fad, I really haven't see that many new builds going yanmar lately.
 

Albert Jr.

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They are very small footprints. Therefore they fit under deck much better than the competition. This makes them popular in the small, recreational DE boat market. Truthfully, I feel like they were kind of a fad, I really haven't see that many new builds going yanmar lately.

Interesting, thanks.
 

hntrss

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I would hate to know how much Yanmar parts and service cost in Curacao! Nice place to be this time of year!
 

Albert Jr.

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I would hate to know how much Yanmar parts and service cost in Curacao! Nice place to be this time of year!

Indeed.
Wish the weather was a bit cooler to be honest, right now we're at about
36 degrees Celsius so about 97 Fahrenheit.
 

plowin

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I do not know the answer for sure but I would guess that horsepower to weight ratio has somethingb to do with it.
 

jojobee

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Perhaps it is reliability! Yanmars developed a great reputation in the sailboat market. They have some crazy market share in the USA. Something like 88%. A lot of older boaters that get out of sailing are drawn to the single engine doweast style boats. They want what worked for them in the past. Yanmars also powered the John Deere tractors and this added to people's perception of reliability. Yanmar is a great engine and not some fad. They are the largest privately owned engine manufacturer in the world.
 

djmarchand

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The Yanmar 6LY 370 hp and the 6LP 315 hp engines are the two engines that are most often found in downeasters. They are great engines, but... I wouldn't use one on a commercial boat unless it was the only thing that would fit.

Why? They are lightweight- the exhaust manifold is made of aluminum, they have a higher hp to liter or lb ratio than a Cummins, Cat, Deere, etc. Their lower end isn't as robust as a Cummins B. And their parts are expensive at least relative to a Cummins.

For all of these reasons you rarely see them in a commercial lobster boat. But in a recreational boat, yes no problem.

David
 

BillD

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Can't get the 6ly series NEW, only in reman/recon.

Now its the 370hp. v8

The mechanical 6ly series 315/370 (no longer in production) were great motors when maintained to spec and propped correctly.

Power to weight and a much smaller physical footprint compared to "American iron" helped make the sale.

A few Maine built DE manufacturers molded their cockpit/engine decks around the low profile Yanmars offering "no engine box".

Now the new Yanmar 370 V8 or inline sixs are physically larger and more complicated don't "fit" as easy under the deck.

Me...I'll stick with American marine diesel iron. :D
 

FlyingConnie

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Yes Yanmar is promoted by Mack Boring as a recreational engine. No different then when a cummins 5.9 puts out 425hp or even 480hp. Smaller lighter yanmars makes downeast boats faster and burn less fuel. I own a 6lp and I'm fine with a 500 hour per year engine. I looked at a real nice boat but didn't buy with a 3116 or 3126 in it.
 

eyschulman

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seattle
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The Yanmar to stay away from is the 6ly 2a series. Particularly if over- propped or poor exhaust geometry. As said above the 400+ HP Yanmars are M4 pleasure type motors and take careful running and maintenance to go the distance. They are light and will fit in a tight cubby hole and put out a lot of power and HEAT. And it is the heat that often does them in 1300 degrees at Ex valves at WOT. These Yanmar motors do not have the reputation of their smaller models and it would be a mistake to think they are the same.
 

05bill

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cape cod
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rp, willis beal
yanmar

i have the 370 in a de. i use it for pleasure, and i chose the engine for its reliability. join boat biesel or contact tony athens at his shop on the west coast . his brother has two 370s in his commercial boat and he has several thousand hours of trouble free running. these engines need to be propped properly, mine is under propped and i run at less than 20% off the top. i maintain it according to maintenance schedule, change the anti freeze with the correct type, use rydlime to clean coolers. stuff that i like to do. every year we do a oil sample and we have very little wear year over year. run about 100 hours if i am lucky each season. 05bill
 

BillD

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i have the 370 in a de. i use it for pleasure, and i chose the engine for its reliability. join boat biesel or contact tony athens at his shop on the west coast . his brother has two 370s in his commercial boat and he has several thousand hours of trouble free running. these engines need to be propped properly, mine is under propped and i run at less than 20% off the top. i maintain it according to maintenance schedule, change the anti freeze with the correct type, use rydlime to clean coolers. stuff that i like to do. every year we do a oil sample and we have very little wear year over year. run about 100 hours if i am lucky each season. 05bill

Outer Banks (Tony's brother's boat)
13,000 hrs. on the Yanmar 370s, still running fine.:D

You can bet $$ that the turbos have NEVER seen water, injectors were never fed anything but clean water free fuel, the engine room was kept spotless, water free, engines maintained to spec and ALWAYS propped to see 150-200 rpms WOT over rated with the boat as heavy as he'd ever run it.

Yanmar 6LYA 370--just under 13000 hours (1).jpg

Yanmar 6LYA 370--just under 13000 hours (3).jpg

Yanmar 6LYA 370--just under 13000 hours (8).jpg

Yanmar 6LYA 370--just under 13000 hours (9).jpg

Yanmar 6LYA 370--just under 13000 hours (6).jpg
 

hntrss

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Its kinda funny his brother has Yanmars. Tony sure doesn't seem to love them.
 

BillD

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Its kinda funny his brother has Yanmars. Tony sure doesn't seem to love them.

I know for a fact Tony liked the 6lys and the 4lHs and he sold a bunch back in the day.

I also recall him saying once that the 4LHs were one of the best 4 cyl Tier I
marine diesels ever produced.

Pretty sure he doesn't care for the new electronic Yanmars.

He may see this and chime in.
 


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