Yanmar 6LYA-STP engines

[Comodave]

I am going to look at a boat with these Yamnars in it. I am not familiar with Yanmars at all. Anyone know about these engines. The boat is a 2002 and the engines have about 800 hours on them. Any known issues with these engines? Good, bad or ugly engines?

 

[porman]

We have these in our boat. They are 2003 model year and had 800 hours on them in 2014 when we bought it. Currently have just over 2000 hours. They have been trouble free. I have done all the maintenance, including oil and filter, fuel filter, v-belt, air filter, raw water impellors, coolant changes, and valve adjustments. This spring I removed the aftercoolers, oil coolers, heat exchangers, and transmission coolers for cleaning and resealing, the first time they have been off. They were all spotless inside. However the boat always gets a 2 hour run in fresh water after being out in salt water. Parts are a little expensive, but what marine diesel parts aren't? There is a version of these engines with 440 hp, mostly used in sportfishers I think. They had some valve and head problems. From what I have read the 370 hp versions are very reliable.

 

[sickatea]

I did my homework on these engines prior to purchasing my latest boat with one. It appears to be one of the more solid motors that Yanmar manufactured. This being the 370hp motor doesn't have the issues with valves dropping out that some of the 6LY2A-STP (440HP) had occur.
My 2004 Mainship had great service records and had 1000 hours on the motor when I got it. As preventive maintenance, I had the heat exchangers taken off and sent them off to a radiator shop to clean and pressure test just to be on the safe side.

Good luck with the possible purchase, I don't think you will be disappointed with the motor.

-Rich

 

[DavidM]

I owned two Yanmar 6LY 370s on two different boats over the years. They performed flawlessly. The only thing to be careful of is the after cooler. It needs complete maintenance every 5 years unless fresh water flushed rigorously.

Take care of the aftercooler, change fluids routinely, keep the fuel clean with good filtration, prop it right and don't run them too hard (at least 400 rpm off of wot) and they will give you great service.

The Yanmar 6LY along with the Cummins 6BTA are two of the best marine engines made in their hp range.

David

 

[Bacchus]

Agree with the above and treated correctly you should do very well.

 

[Comodave]

Thanks to all for the info. As to the fresh water flush, the boat has been in fresh water it’s entire life so that should be good. Does anyone have any spec sheets on it?

 

[DavidM]

Spec sheet attached.

David

 

[Comodave]

Thanks, David.