Yanmar Running Time

[tborcher]

I've got a Yanmar 3YM30AE diesel on my RT-21. Logged 20 hours so far. Question is: What is the maximum amount of time the engine should be run at about 2800 RPM's before it should be given a "break." I'm about to take my first significant journey down the Tennessee River and the next marina from mine is about 30 mile away which I figure may take 4 - 5 hours. Can I go non-stop is sort of what I'm asking.

 

[LAKERtoo]

.. I'm not an expert, but my 3ym's sweet spots, are at between 1800-2000 rpm and about 2200-2400 rpm .. that's where everything seems the smoothest in terms of synchronized vibrations between the prop and engine .. 2800 shouldn't be an issue for 4-5 hours, but if it was me I'd be listening for those sweet spots and varying rpm once in awhile .. you should be able to maintain 6.5 knots or so at a lower rpm than 2800 .. Rob

 

[lone ranger]

I am certainly no expert,BUT..the motor is also designed as generator motor and those times run all out all the time.I also spotted a tag that states 3600 rpm is peak H.P. .now my history with diesels has always been run em hard,and I have.so by that theory by only running at 3200rpm we are not getting full punch out of that lil 3 cyl.

 

[sheral]

Personally, with only 20 hours on it I would run it at varying speeds for a bit longer. But I will also throw in my disclaimer - I am no expert... 🙂 I think the short of it is that you just have to run it in a ‘reasonable manner.’ 80% max is reasonable once it is broken in. I have talked to diesel engine manufacturers that have said the smaller diesels do just fine with trolling speeds most of their life, and that pure synthetic oil at first oil change is fine... all things that others would argue. So I guess my point is that you are going to hear a lot of opposing information on the subject. 🙂

 

[tborcher]

The Yanmar manual states that after 10 hours of "low" rpm break-in and up through the next 50 hours the engine -- still in a break-in period -- should be run about 400 rpms below full throttle for about 15 minutes of each half hour; 200 rpms below full throttle for 10 minutes of each half hour and full throttle for 5 minutes. "Full throttle" seems to be about 3000 to 3100 rpms. It specifically says between 10 and 50 hours is not the time for slow cruising for any period of time. From the Tugnuts "replies," it sounds like I can pretty much go the 5 hours without stopping. If anyone disagrees with that, sure would like to hear from them. Thanks for all your input. Tom

 

[rt11002003]

Best to follow Yanmar instructions, to the letter (as closely as possible). Sounds to me like Yanmar issues different instructions with every change of the moon. None of the Yanmars I've owned had those instructions. But, never mind, do as the mfg. says; their warranty is based on you following their instructions.

Bear in mind there are TWO max rpm limits. One is the max allowed by the governor with the prop/engine out of gear. On my 2007 and my 2009 R21EC's, that was 4,000 rpm, +- 25 rpm. The second max is MAX RATED RPM, which is what the engine will pull with the installed prop in gear. MAX RATED RPM is the number/limit used for break-in and operating the engine; also used to select the proper prop.

"Full throttle" is MAX RATED RPM.

 

[SGIDAVE]

I've got a Yanmar 3YM30AE diesel on my RT-21. Logged 20 hours so far. Question is: What is the maximum amount of time the engine should be run at about 2800 RPM's before it should be given a "break." I'm about to take my first significant journey down the Tennessee River and the next marina from mine is about 30 mile away which I figure may take 4 - 5 hours. Can I go non-stop is sort of what I'm asking.

HEllo Tom,

A direct answer to your first question: indefinitely.

And your second question: yes.

In my experience, 2800 rpm is "pushing" it. The boat handles it fine, but the noise is more fatiguing than at a more 'cruise-comfortable' speed of approx 2200-2400 rpm.

Enjoy your boat!

dave

 

[Two killicks]

For the noise and vibration, 2200-2400 rpm indeed. This is were I keep mine too, you will still make a speed of 5.5 knots or so!

My engine has 275 hours so far, I go full throttle minus 200 rpm (3700-200=3500 rpm for my tug) for 5 minutes every hours.