Yanmar 6LP - STZE 300hp engines -any known issues?

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crazy4557

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I'm currently buying a Sealine S41, contrary to an earlier post when I was looking at a Princess V42/Targa 40! My budget seems to fit this boat better!!
Anyone know any issues with the Yanmar engines. I've heard no real problems and they seem to be well respected. Can anyone blow this theory out of the water?
Also, S41 Sealine's anything to look out for apart from the standard build quality?
Andy
 
The only problems with this set up is not so much the engines, but the Mercruiser Bravo III drives. The Yanmar engines had so much power/torque that the drives were heating up and destroyinbg themselves - the problem seemed especially prevelent on the S41.

The fix was a water spray to the outside of the drive to keep it all cooler, so it is worth making sure that your boat has had this modification done. If you are buying the S41 that Essex Boatyards have, talk to them about a two year mechanical warranty for the engines and drives. Will probably be around £1500 per engine, but if you have a drive go you will be well covered.

As for the S41, I think they are a good boat with a serious amount of room inside. Make sure you have a good run out on it, some people reported the S41 was prones to quite a bit of chine walking but I have never been on one to experience it - best just take a run out and see if it suits.
 
Westline .....That's an interesting fault about the drives I will check that issue. I have a 12 month warranty but will definitely look at a 2 year one for peace of mind. As you say it's a good boat and huge space. Your help is appreciated.
 
I've heard people talk about supposed handling problems, but in a recent MBM Cruise, on each leg, the S41 was the second boat in each time (only overtaken by the Windy 37), 22-24kts cruise, no sign of "chine walking" or anything else strange. It could be that these issues are only apparent at much higher speeds (that most people very rarely go at anyway).

It seemed to cope with bumpy conditions very well, mainly by virtue of sheer size. It's never going to be quite as smooth upwind as a Targa 40, which has a more pointy hull, though.

Good cockpit and cabin layouts too. Even I wasn't banging my head on things.

dv.
 
Here's a tip: If if has the Bravo3 drive, RUN don't walk away.

As said above, the Bravo 3's simply couldn't handle the torque of the diesels resulting in over-heating and the gear eating themselves up. So Mercruiser came up with 2 solutions:

1) Heat - They designed a 'shower' which bolted onto the out-drive. When you moved, it would push water up onto the drive keeping it cool

2) The Bravo3X was released - Same out-drive with stronger internals

However there are still failure reports with the Bravo3X - The general feedback I got when looking into a Bravo3(X) drive in the past was to not bother because it's not worth the risk of failure - I took peoples advise and i'm happy with my DP 290out-drive, never had a days bother
 
These are smooth, powerful engines but they will destroy a bravo3 in no time.

They also can destroy a 3x, if the leg is allowed to get too hot.

There are 2 resolvable issues and they both involve keeping the drive cool.

1, the yanmar needs more cooling water than the leg can provide, so builders blank off the water inlet in the leg (using an official mercruiser kit) and use a through hull.

Don't accept this - you need through leg water AND through hull water through a Y piece to the engine. Use 2 filters and you get the added advantage that you don't wreck your impellor of you get a bag over the inlet but you can see that it's blocked. The water heading for the engine helps cool the leg.

2, fit a drive shower.

Keep them cool and its a good package and you'll get a deal as people are scared of them

Yanmar take the P with parts prices but most are toyota landcruiser.
 
It's an "if". Some of these were fitted with the Boring-But-Solid Bravo II.

Also, if you're getting a good price enough on the boat itself, you could keep aside £10k for a couple of new outdrives and still be quids in. Even 290-DP's go bang sometimes, e.g. if fishing line damages the shaft seal and all the oil drains out /forums/images/graemlins/blush.gif

After all, the boat has already covered 274hrs. Might be worth seeing if the serial numbers on the outdrives match the original docs!

dv.
 
Maybe a silly questions but:
Can you fit the Volvo D290DP legs to the Yanmar's? Adaptor plates ??
How do you indentify the Bravo 3X from a 3 and Bravo II? this boat has duo props...is the bravo II single prop?

I didn't notice any'shower' when I checked out the legs, would they be obvious?
Andy
 
Can you fit the Volvo D290DP legs to the Yanmar's?
Adaptor plates ??
>Not sure, but it's something I have never seen, so I would guess "No".

How do you indentify the Bravo 3X from a 3 and Bravo II? this boat has duo props...i
s the bravo II single prop?
>Bravo II is single prop. Bravo 3X has an "X" on the upper unit.

I didn't notice any'shower' when I checked out the legs, would they be obvious?
>Look for water tubes / spray thingies under the transom.

dv.
 
Was there some issue posted in the past about one of the 300, 310 or 315hp 24valve engines being a bit smokey due to over cooling at low rpm? I beleive the 250, 260, 350 and 440hp motors are all excellent, the only query was with the 300!
 
I feel that I am a bit of a party pooper on this site.

Yes there ARE issues with the 4 valve LP engines.

The Yanmar LP Series is a big player in the U.S. diesel market. They run up far more hours than we do, and and yes they have hit some big problems. Engine unlike the LY series is a Toyota motor marinised by Yanmar. The LP had developed a very good reputation in the U.S. However during last year a long standing issue came to a head.

At just over a thousand hours owners would notice a slight tick, just as they pulled the throttle back. If this is ignored the engine suffers a dropped valve. Result varies from plain nasty to catastrophic.

Owners banded together and the result was a Class Action Law Suit against Yanmar. Yanmar capitulated and to their credit have provided policy repairs and expended warranty to literally thousands of engines.

The valve gear rework is a good fix, and the valve drop problem went away completely.

E. P Barrus KNOW they have literally hundreds of engines in the effected engine serial number range, however they are happy to let the matter slide in the UK. By the time an engine fails it will be of a sufficient age for them to shrug their shoulders. Typical example of boaters here getting shafted.

I do not use this site very often and am not sure how to post j pegs, however I can mail copies of the Class Action Law Suit to anybody who is interested.
 
That makes interesting reading...especially the UK customer's potentially being hung out to dry by Barrus ! Not the first marine engine company to treat us this way by all accounts.
Have you any knowledge regarding the Mercruiser outdrives fitted to this engine as the general consensus is they are under engineered for the Yanmar 300hp motor?
Andy
 
In the U.S out drives are for ski boats and then only as a second choice against shafts.

98% of the Yanmar LP's were on shafts. I do know that the out-drive needed an external spray head, now that sucks as good engineering.
 
You'll need a new bell housing and doughnut to fit to Volvo - that's if they'll fit at all and I don't think they do. Too difficult.

Bravo 2 is single prop. 3 and 3x is twin prop. The stickers will say or to be sure check out the serial numbers on the parts diagrams here.

Showers are obvious and you can buy them on ebay often - they look like this but this is for an alpha. An alpha is smaller but a shower for any bravo (1 2 or 3) will fit.
 
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