Considering a boat with a Yanmar 6LPA-STP 315.

[Bill Stenger]

Hello again guys. My buddy is replacing his charter boat with a larger one and gave me a very fair offer to buy it. I currently run a similar hull with a 250 cummins. I am nervous of the Yanmar 6LPA-STP 315. It has 5300 hrs. since rebuilt. It ingested water when it was nearly new @1000 hours. He has owned it for about two years and 1500 hours or so. Fluids and filters changed regularly. Exchanger and after cooler have not been serviced since he has owned it. I did not think to take any pictures of the engine or layout. Totally slipped my mind. I feel these are not 10-15000 hour engines like the cummins.

It does smoke a bit at idle and he feels it is injectors which he said he would replace. Smells like fuel. As soon as he puts it in gear it quits smoking and runs great. Currently under propped which is good. I believe he said wot is 4080 rpm so it could stand for more pitch.

Should i buy this with intention of needing to replace the yanmar with a cummins down the road? I generally put about 200 hours or less a year on the boat.

Does this yanmar have a timing belt?

I feel the yanmar is more complicated than my 6bta. I am curious of your opinions and experience guys.

Thank you.

Topic

[Tony Athens]

If the boat is “a hard to get up on type hull”, dark transient acceleration smoke can be normal..

Doing the aftercooler is always a good thing to do every 2 years or so if the engines sit with saltwater is them..

[Bill Stenger]

Thats good to hear Tony. I am moving forward with the purchase. I plan to change the timing belt and tensioner immediately. Then aftercooler and hx soon after.

Went fishing on the boat yesterday and just before the turbo fully spools and it jumps on plane there is a large black cloud of soot for a moment. Then it clears right up. Hopefully cleaning the aftercooler up will resolve that.

[Tony Athens]

As Rob eluded, the Yanmar 6LPA can treat an owner right for many 1000’s of hours.. Based on what you have posted, the engine is running easy, but much depends on the Marine Age component as the seawater system is more complex than a Cummins and the engine is “coolant type” sensitive.. Parts support is still OK

I personally think was a great engine was sorry to see it go way, and it also filled a unique size vs. power ratio niche in this market….

This particular engine and the 4LHA’s were the ones they should have put their $$ into to meets EPA T3 spec—————————-IMO, Yanmar blew it big time as this was the main reason I walked away from them.

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Bill Stenger

[Bill Stenger]

Here is some terrible photos that were sent to me. The engine was pulled recently to change the coupler between gear and engine. And he painted it this gray color and changed all the hoses. If that elbow fails it is still downhill to the engine so it would need a riser if i kept the yanmar.

[Bill Stenger]

Thank you Rob! With the current owner he is either running it at idle trolling or cruising about 3=3200 rpm. He never runs it at fast cruise unless out running a storm or something. Fast cruise is 25 kts his normal cruise is 21kts. I have fished on the boat about 40 hours prior of ever considering owning it and its always run @ 21kts. But no one knows the history of fuel consumption before current owner.

Thats slightly reassuring about the aftercooler. I will put it second on the to do list after the timing belt. Which i know has not been changed in at least 1500 hours. As well as the heat exchanger. I do not think he regularly changed the coolant. I know he had to remove the engine and gear recently to change the torsion coupler. Likely changed a portion of coolant at that time.

Any clue of the value this engine used? I would love to run it for a season and sell it and install a 355 6bta in its place!!

I like that it actually has alarms my old 250 doesn’t have a single working alarm that I know of. It was on the to do list. I watch the coolant temp like a hawk while running! And the yanmar panel is actually in the electronics box unlike my cummins that is out in the open and severely weathered.

This does not have a dry rise manifold. The elbow is higher than my cummins elbow. So there is a chance it will need a new turbo as well. I will have to pull the elbow and inspect the turbo once in my possession.

Seems the exhaust is only 4″ or 4.5″ heading to the transom. So if i do install a Cummins in the future I assume it would have to be 5.5″ or 6″ so that is another project for the swap.

I requested some pictures. Should have them tomorrow hopefully they are quality.

Thanks again guys!!

[Rob Schepis]

Bill Stenger wrote:

I feel the yanmar is more complicated than my 6bta.

The first order of business that makes owning the 6LP a little more complex than a 6BTA is the fact that anything and everything you could ever need as to OEM, upgrades or plain old support is right here on the forum, the website, or a phone call away. The 6LP isn’t terrible support wise but it is going to take a little more leg work on your part.

Can you get pictures of the install and conditions of things? Have your buddy send to you.

5,300 hours since rebuild is a sign that whatever the water ingestion issue was was corrected and the install, the maintenance regimen and the operator(s) are good.

As to the how much life is left in it, there is no definitive answer to that. Any idea how many gallons of fuel it has burned – in other words, how is this boat used day in and day out? Fast cruise, trolling, taxiing…….

If marine age has not taken a toll and you are going to put on ~200 hrs per year there “should” be many many recreational seasons of life left.

Current propping is a very good thing.

Yes on the timing belt.

As to the intercooler – you have to be concerned but do not have the same Grim Reaper mindset as is the case in dealing with an overdue Cummins SWAC. Yanmar did a much better job with mixed metal aftercoolers than Cummins ever did. I just performed a first time servicing on a 6LP intercooler on an engine that was put into service new in 2001, saltwater from day one. The core came right out with a strong push of the thumbs and the core and the housing were perfect. Others with the 6LP were not so lucky but it definitely has better odds in your favor than the Cummins would when it comes to a neglected or overdue aftercooler.

I’ve personally owned three 6LP’s and would never not buy a boat because of one. If ALL was identical between the two I would take the 6BTA for the support, parts pricing and simplicity but the 6LP is for sure the runner up over any other.

The Yanmar is usually factory equipped with a better alarm system than the Cummins. The OEM panel lights and buzzers are much louder and brighter. The OEM setup should include raw water flow (on top of the intercooler at the seawater entry), coolant level (on top of the coolant header tank), water in fuel (at the base of the on engine fuel strainer).

Many more zincs and numerous relays does and to some complexity and things in general are “tighter” to work on than the 6BTA but that’s why it fits well were others don’t and is a nice drop in replacement for the small block gasser.

The Yanmars w/ their aluminum exhaust manifolds are coolant sensitive engines. Be sure he is using proper coolant and it’s on a tight change-out interval.

That’s a start……..

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Tony Athens

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