Yanmar 6LYA-STP marine engine with 370

[Bronson]

Looking to purchase a 405 Cruiser Yacht Motor Yacht with twin yanmar 6LYA-STP diesel engines with 370HP for a total of 740HP. Dry weight of the boat is 31,000 lbs, will this be enough power to get the boat on plane easily or will this be an issue?

 

[Barry]

Playing - Cruisers Yachts 420 Express (2004-) - | Cruisers Yachts | Powered By BoatTest.com | 31 http://www.boattest.com/oem/31/boats/733/0/
This is not the exact boat but you will probably be able to find reference to your 405
There is at least one Cruisers yacht owners forum, and many many other sites that discuss that particular manufacturer and even with the Yanmar engines

Yanmar had a recall on one series of 6LYA evidently, but I could not find which one. Quite serious and they had a complete recall, refit, etc. I would try to find this before buying to ensure
that this was not the engine in question. You need to talk to a Yanmar distributor query him on which one that it was.

Boattest is an invaluable source for info on different boats

 

[Bronson]

Thank Barry, I will look into the recall. I thought about going to the Cruisers forum, but wanted to make sure I got a non biased opinion.

 

[Ajwpge1]

I just purchased this exact boat with 370 hp yanmars. Brought the boat back from Baltimore to Buffalo, NY last year. I would never own another boat with yanmar engineers again. So far I have spent over $10,000 working with a mechanic that Mack Boring told me to use trying to get ride of my black soot issue.... Will not use him again!!! Now I am trying to troubleshoot the problem myself. I have done this work to both engines: Valve adjustments, turbo wash, rebuilt injectors, he even adjusted the smoke limiting screw on fuel pumps, and re-pitched my prop because I was only getting 3100 rpm. Now I get 3650 rpm with same amount of black soot. I decided to remove both intercoolers this week and clean. I will see if it make a difference this weekend. I have been talking to other 405 owners with the same engine in different parts of the country with the same issue. Like I said I will never own another boat with these POS engines...

 

[A1 Marine diesel service]

The 6LP is 305-315 hp.

 

[Barry]

I just purchased this exact boat with 370 hp yanmars. Brought the boat back from Baltimore to Buffalo, NY last year. I would never own another boat with yanmar engineers again. So far I have spent over $10,000 working with a mechanic that Mack Boring told me to use trying to get ride of my black soot issue.... Will not use him again!!! Now I am trying to troubleshoot the problem myself. I have done this work to both engines: Valve adjustments, turbo wash, rebuilt injectors, he even adjusted the smoke limiting screw on fuel pumps, and re-pitched my prop because I was only getting 3100 rpm. Now I get 3650 rpm with same amount of black soot. I decided to remove both intercoolers this week and clean. I will see if it make a difference this weekend. I have been talking to other 405 owners with the same engine in different parts of the country with the same issue. Like I said I will never own another boat with these POS engines...

I would try a couple of sites
Boatdiesel.com They offer a ton of information of all types of engines and more than likely have a solution to your problem. This is a paid site, when I joined for a year, it was about $25 US
They have detailed information on a multitude of engines, transmissions etc. Almost bought a 40 footer with Yanmars but from somewhere in their website I found that there was a major recall on the very engines that we were going to buy . Saved a ton of money.
As I understand, Tony Athens was a main moderator of the site and he would respond to specific questions backed with years of experience. I believe, but cannot be sure,
that he does not partake in this site any more but the information may still be there

BUT now he has some relationship with Seaboard Marine, a company working on Cummins Yanmar etc and is able to offer the same solutions. I would contact them to
see if they can help