Yanmar 4cyl vs Yanmar 6cyl

[Raymond Slingerland]

In general, for my search for a boat I have searched only for those with Cummins Engines. Parts are cheap and available, and mechanics are readily available to work on them. However, there are some boats that I might consider that come up with the Yanmar engines such as the 6LPAs and the 240HP 4 cyl. I have eliminated the 6 cyl from consideration for such things as Valve seal issues and more stringent maintenance requirements. But how about the 4 cyl 240s? Compared to the higher HP 6 cyl., are they less demanding, with less maintenance requirements, checks, etc. ?? Trying to determine if the 4 cyl Yanmar might be a different machine when comparing to the 6 cyl. as far as reliability and maintenance costs are concerned. Thanks

Topic

[Tony Athens]

Bill,

I’m on your side…………Cummins never produced an engine in this size that could come close the the overall quality of 4LHA…..IMO , 4BTA was sad attempt……To bad they Yanmar never made it in a Common Rail engine but instead wasted their $$ on the 6LY (that engine could never compete w/ the QSB) and those “BMW chainsaw diesels” that are already obsolete…

I will mention the 3 yr old QSB 4.5’s in my Bro’s boat are very nice.. If Cummins wanted to get into the 4 cyl marine market again, I’d consider that one or their newer ISB170 , as a good candidates if “marinized right”

Tony

[Raymond Slingerland]

4cyl yanmar

Bill, your reply is most appreciated. You have hours on those engines which give me some good confidence that they are worth considering. I will continue to consider them. As a matter of fact the Bertram, with the lower helm is an example of the boat that might work for me, but if flybridge has to have the lower helm. Want to cruise 20 knots, in air conditioned comfort, and have to travel 50 miles to the fishing grounds. Would prefer 31 to 34 foot boat, since I have large family but the Bertrams that size wouldn’t make it with just the 240s, so it is a trade off. Know the Bertram is deep V and heavy but some of the other 31-34 boats might make it with the 240s. Thanks for your post.

[Bill Fuller]

Raymond,

I have been running set of the 4cylinder Yanmars for the past 18 years. So ask my anything you want about them.

If you are looking at boats that a properly powered with this motor, you simply can not go wrong. Many out there, including myself, will tell you that this is simply the best motor out there in this HP range. Personally, I would much prefer the 4LHA Yanmar to any Cummins. Tony may come down on me for that, but maybe I can get away with the statement since he installed the Yanmars in my boat. I know a number of people with them and all are extremely happy. I few facts on my personal experiences.

1975 28 ft. Bertram
4LHA-STEs installed in 2000 at Seaboard Marine
5,727 hours
WOT speed about 29 knots, cruise from 15 to 22 comfortably.
Repairs: both torsional dampers after 16 years and 17 years. NO OTHER REPAIRS.
Routine maintenance as described on this site.
I have never so much as even cracked an injector. Let alone replace one.

I do not consider routine cleaning of heat exchangers, after coolers, oil coolers, gear cools, etc. as repairs.

As you can see, I highly recommend the 4LHA motors.

Bill

[Raymond Slingerland]

Yanmar 4 vesus 6.

I understand hp, versus, size etc., for a given performance so that is a consideration. I also understand use and care is a big factor. However if the boat has the 6 LPA engines than I have to determine if valve seal was an issue and if so was it fixed. Also reading the forums regarding the 6 engine hasn’t been encouraging. Is the 240 history any better or should I give up on Yanmar and stay with Cummins. I am unable to do the very through detail investigation needed to fulfill your approach, when boat is 1000 miles away. To some extent I have to roll the dice. Now, IN GENERAL, my understanding is that my odds are better with a Cummins than a Yanmar. Parts are cheaper and more mechanics can work on them. And in a heavy duty use they hold up better. So, if I roll the dice is the 240 a better risk than a 6LPA? Thanks

[Tony Athens]

IMO, both engines were “World Class” when they left the factory.. The valve seal thing on the 6LP has come and gone..

What shape they are in now will depend on how they have been set-up & run, & maintained per each engines needs & wants….

As to what engine–That will depend on the vessel and your need for speed. Yes, the 6LP is more complex, but put a 4LH into TOO much boat vs your needs., it it will not do you right.. But also, a Cummins 6BTA 5.9 is more complex the a Cummins 6BT 210 5.9 and requires substantially more care than the 210 version

You need to get real specific in the boats you are looking at , post all the specifics, and then maybe we can give you a better answer.. If you look at a vessel in person, be sure you have a camera –This forum needs to “see” what you “see” if you want the best possible feed back..

Tony

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