How many hours are the Cummins good for

[Nolabama]

How many hours are you guys getting out of the Cummins vs the Yanmars before they become cores ?

3k?

If a QSM 11 owner wants to chime in feel free.

[Charlie J]

Ive heard 33,000 hrs on some yanmars
with just regular maintanance

[ford351c594]

some food for thought, 1 hour of usage is considered 33 miles at a normal usage. Extreme duty is considered 25 miles after 1 hour. Being as it is a boat I would consider every hour the equal of 20 to 25 miles of wear similar to a car or truck. You can interchange this into the standard life of an engine accounting for gas, light duty diesel, or heavy duty diesel.

That also supports Charlies post above as many consider yanmars to be million mile engines.

[Rawleigh]

Just for comparison, I have 4,989 hours on my diesel truck with 200,400 miles on it.

[bob lico]

try cummins versus catapilar . 1500 boat repairs a years catapilar/cummins/mtu/ about 1000 to one average NO 6 cyl yanmar over 2000 hours without heads self destruct . so bad the major northeast yanmar machine shop and major repair service pulled out of northeast no factory warrantee center available , yanmar is out.cummins 6bta-m3 rated at 30,000 gallons of fuel so changing that into hours you can take a average of 5 gal per hour especially if you troll and run up hours at idle .so 6000 hours or 5000 with more cruise time with cummins rated oil. (vavoline blue same as name plate next to oil filter)

[Tommy]

Come on, Bob, you don't have to call someone's question ridiculous! Most of us are not in the marine or mechanical service business like you and a Bruce, so we have to ask questions to learn. Please go easy on us greenhorns!

[farmer]

We run cummins 5.9 and 8.3s in large farm tractors under heavy tillage probly similar to boat usage . Change injectors every 5000 hrs . Engines good to about 12000 hrs. Then re ring and bottom end , good for 5 to 6000 more. Running 2200 rpms all day .

[bob lico]

sorry tommy the bastards cause so must aggravation to many people and friends .Sometimes you become humiliated when you cannot help them ,definitely should have been a class action suit against yanmar even at first look at the engine hmmmm lets see the last removable oil cartrige used in american was 1967 what makes you think for one minute a mechanic is going to go on land to parts cleaner and take heavy metals from bottom of can !!!! jusy plain stupid along with 1984 the last of fan belt in automotive engines but not yanmar they saved money on idler pulley, and tensioner of all other diesels running serpitine belt. not even getting in to the morons running your cam and valves on a rubber belt instead of gears like catapilar,cummins,mtu,mann,volvo,perkins,detroit,mercedes,john deere ,even the Italians . let the buyer beware. farmer it is pretty much known cummins generators go for 100,000 hours all over china whom sent yanmar packing as well as the outback mining regions of australia .

[Yannis]

Yanmar=Toyota= Japan =Precision = Good stuff.

[Marlin]

The Last Mango has 550hp QsM11 and 4500 hours, I have 1850 on my660 QSMs ,never have added a quart of oil ,doesn't smoke

[Nolabama]

ridiculous question!!!! try cummins versus catapilar . 1500 boat repairs a years catapilar/cummins/mtu/ about 1000 to one average NO 6 cyl yanmar over 2000 hours without heads self destruct . so bad the major northeast yanmar machine shop and major repair service pulled out of northeast no factory warrantee center available , yanmar is out.cummins 6bta-m3 rated at 30,000 gallons of fuel so changing that into hours you can take a average of 5 gal per hour especially if you troll and run up hours at idle .so 6000 hours or 5000 with more cruise time with cummins rated oil. (vavoline blue same as name plate next to oil filter)

I've worked around diesel engines most of my life. This was what I was looking for.

I don't even know who would be a yanmar dealer here. I hate Cummins MidSouth with a passion tho. But. That 5.9 or bigger recon motor is something I can work on. I really don't want any electronics.

[Bill Fuller]

In the case of Yanmar, one must ask which Yanmar, as there are a variety. Some are very good and others not so god (bad).
The 6LP is a marinized Toyota. Driving the overhead cams with belts may be questionable but very common in the automotive industry and it is an automotive engine. Personally I think it is not the way to do it. Still a pretty decent, high HP, light weight engine. The BY series is and was, not so good. Again marinized BMWs. There are others in this category.
The lone Yanmar designed motors in the class we are talking about, the 4LH and 6LY are great motors, even though as Bob says the V-belt system is archaic and sucks. I consider this to be the one weak point on the 4LHA. FYI, there are serpentine systems available for these motors. Actually, in my opinion, in many ways, the 4LHA and 6LYAs are easier to maintain than the 5.9 liter Cummins. I expect to hear lots of screaming feedback on that statement!

Currently, I have 5,500+ hours on my 4LHAs. They are used in the manner Bob describes for shorter life span. Run at speed for 30-70 miles, troll all day and then run hard back to port.
At this point they do not use a drop of oil, start instantly, and smoke just a little at idle just like the day they were new.

Needless to say I am quite happy and expect to get at least another 5,000 hours.

The big factor on longevity is how you run your motors and how you maintain them. The best motor will not last long if not taken care of and the worst motor will last a long to time if well taken care of.

With appropriate care, the Cummins is capable of providing many thousands of hours of enjoyment.

Bill

[bob lico]

cummins is very selective on whom they gave franchise agreement thus dealers like mid south had a attitude . when yanmar came to town they could care less it was all about volumn . they gave gave the parts and maintenane manager a stick of gum lets see "can you walk and chew gum at the same time ? good you are a certified yanmar dealer!!!! meanwhile the cummins dealer located in the Bronx ny controled cummins in the northeast so you paid the price no getting around it because the engine after installation had to be cummins certified to qualify warrantee .sometimes in life you may walk down a street or go in a house and be struck with the feeling you have been here before. the first blow up of a stp 6cyl. yanmar was taken apart and it dawn on me hey i have seen this before ;YEP 1954 era 6 cyl. 292 cubic inch chevy,wow same block,rods,crank ,look at the rocker arms .i was totally impressed with the sales wisdom of yanmar this is better then that dude making millions selling a "pet rock" or "cabbage patch dolls" wereby as a parent you had to get one for your daughter at any cost. i immediately remove my 250 hp yanmars from my 31 bertram and sold them for 4 thousand more then i paid. we had a deal with a large local machine shop that worked for a while but when the engine started to pile up with valves that struck pistons and destroyed the cylinder heads the head were no longer availuble so the engine was totaled. instead of yanmar using long proven leaders like garret,huron,holshoh for turbo`s then build there own same with injection. why not use bosch the proven leader only time would tell but no need to be rocket scientist all other marine diesel cruise at 2300rpm cruise and just one manufacturer at 3700 rpm with rubber belt turning those valves--------something gotta give.

[Bruce]

As a former Yanmar dealer, among others, would I buy a yanmar in the US today? No. Mores because I think Yanmar America eats it.
But I will tell you numerous engines I installed and serviced
had over 10,000 hours without any major service as did other brands.
Two pairs of 3208's in dive boats had over 20k with no major.

Its not hard for Bob to get animated and get into the Ford vs Chevy nonsense.

But Bob, tone it down a bit.

[bob lico]

i was led to belive the conversation is on 6cyl. cummins to 6 cyl. yanmar. none of my conversation deals with 4 cyl. yanmar the marina sold a few in 28 ' luhrs and have not seen hide nor hair of them in a long time nor do any come here for maintenace. they are non existant along south shore long island marinas .

[Bill Fuller]

Bob,
Which 6 cylinder Yanmar are you talking about?
There are several.
The most pertinent to this group of boaters are the 6LP and the 6LY. Two completely different motors.
The 6LY is the 6 cylinder version of the 4LH. And I think you agree, is a great motor.
Bill
PS, I am confused, what 250 HP Yanmars did you have in your B31 that you removed?

[bob lico]

i had a pair of 6lp=STE 250 hp (two valves per cylinder).

[Dug]

Bill,

There are a lot of 4 cyl Yanmar owners here too!

D

[Nolabama]

.
Two pairs of 3208's in dive boats had over 20k with no major.

poor captain was deaf by 10k
I love a 3208 but damn they're noisy.

[bob lico]

you have not heard a pair of john deere ----OMG------- the 3208 are quiet in comparison.

[Nolabama]

you have not heard a pair of john deere ----OMG------- the 3208 are quiet in comparison.

lol. Yes. I have a couple Deere generators .at work now... They are deafening

[bob lico]

closing post: there were some very angry people put against the wall politically in a federal agency so they set up a very expensive testing site in maryland to come up with the best diesel engine in the world to power city busses in every city in the usa. busses are the number one polution factor for air polution in city condition a continuous stop and go in the worst possible conditions (hot,cold,elevation consideration,weight changes) every manufacturer considered so good news and bad news for america. cummins 6Cta is the best built diesel in the world fitted with canadian injection for burning compressed gas (we have enough for 100 years ) will be used for every municipality in the usa starting with Boston,greater ny ,LA ,etc. by-product of water and slight carbon dioxide. cummins will expand this to every 18 wheeler truck in usa. the bad,bad news is GE could not beat the germans in electric locomotives so that went to germany!!!! hino from china and yanmar were disqualified. as inferior. take it any way you want to, at least cummins are made in USA.

[ford351c594]

I am actually very very glad I read all of this. After working for Ford for over 15 years, I can 100% say I would never own an engine with a timing belt. We did away with all of ours several years ago for several reasons. First and for most is the cost of ownership. If it is a drive belt it will need to be replaced. Regardless of the cost of manufacturing, the cost of ownership is a far larger factor to the consumer. Meaning it is much easier to get a few hundred more at the time of sale than in the shop later. It also great effects the customers sense of dependability. Being as I used to worked on F650 and F750's with Cats, and Cummins, and internationals, I am a huge fan of the First 2. Cat is so simple and that is what makes it awesome. Cummins had amazing durability but far less power. The only thing I can say about Cummins is they had one sucky warranty policy. The core take back is terrible. I can't tell you how many $ and or parts we had to eat in cores. Sure if there is a rod hanging out the block that is easy, but a contaminated fuel claim that melted pistons and valves and ruined injectors is still a usable core. Not to Cummins, here comes you 2k back charge the dealer.

Also, as bob said, the cummins dealer here in New Orleans can have some major attitude issues. It changed a bit when all the Ford Dealers around here picked up Cummins certifications and they were no longer the only game in town.


one last thing... ( I do believe our 3 cylinder uses a timing belt, but I mean come on.... its a 1.0L 3 cylinder)

[bob lico]

talk about cost of belt change. some years back i wanted to buy a Fararri spyder so i was in conversation with one of my old customers ,he own a 18 car garage fill with them and lanbo`s he said "before you buy by make sure the timing belt was changed they need to be changed every 18,000 miles . Big deal a timing belt then i found out the engine must come out of the car to change belt and five state area around new york charges $17,000 to change timing belt. a Fararri uses the belt to run the engine at 8000 rpm with less friction ,maximum horsepower for displacement size and cost no object. putting a timing belt in a diesel is just getting maximum return on there dollar. get in sell as many as you can and bail out!!! smart business men.

[scot]

Two pairs of 3208's in dive boats had over 20k with no major

Now there's a engine Who can't like a V8 design with 600+ cu inches. Only down side is no liners, but the same on 6B. Cheap and easy to replace liners makes the 6C king of the hill.

Of course, I'm a die hard DD guy. But the noise!! I have a 471TA at the house. I "was" going to put in the 25B, but I just didn't think the wife and grand kids could take the noise. No where to hind from it in a 25ft boat.

For sale: Detroit 471TA.