Be carefull with Yanmar!

[HeinSdL]

Too bad to hear about these issues, but....

Like thousands of others I also have a Yanmar (4JH3E + SD40) and have studied forums such as this one and many other sources of information meticulously, my aim being to get to know this unit inside out. It's a piece of my boat which I want to be able to rely on 100% especially in tricky situations (getting into port in bad weather, crossing shipping lanes, etc). It has not let me down in the worst of conditions and the few problems I have had (slipping clutch, air in fuel) were fairly easy to resolve. So I would say I am really happy with my Yanmar, it's a beautiful piece of kit!

Having said that, learning from others is excellent and I would love to hear what was wrong with the abovementioned Yanmar(s) (apart from forward and reverse being the wrong way round, that is not really a Yanmar issue). Maybe we can all learn and perhaps even help out a bit.

[Starblossom]

I have a Leopard 48 with 3000 hrs on my Yanmars. The only problems I have had is with the gauges not working properly and neither I nor the Leopard people have been able to fix them and the cone clutch on the SD50 has to be lapped or repaired at unexpected times. 1 clutch failed at 600 hrs and the other one failed twice, once at 1300 and again at 2700 hours. I believe this is routine clutch maintenance with the SD50 cone clutchs. I have also had a leak in one of the SD50 below water housing that I had to have repaired. Otherwise they start and run alike a charm.

[Cheechako]

Not wild about Yanmar, but going ahead in reverse sounds like a control/cable problem not a Yanmar problem...?

[BrianGJS]

It appears you have some good leads from the replies you received. I wish I was so lucky! I particularly like the Deny, Deny Deny response as something that I have also experienced. Although, not the same engine, my Yanmar 6LYA-STP suffered a broken crank shaft at around 1100 hours resulting in a total reman at a cost of about $55K all in. The kicker is, I have two of these engines! Good luck.

[partingclouds]

My Yanmar is nearly 40 years old and runs like it's brand new...

[Symphony]

bummer to be without an engine on a boat.

other than the crankshaft on the 6LYA-STP (370hp turbo) - it sounds like all the complaints and problems are related to Sail Drive. is this fair?

[mowerandy]

No issues with my old Yanmar. 44 years old, had about three oil changes, a singe water pump service and an exhaust elbow in that time. One stale fuel issue, and a single injector pump rack adjustment required. Nothing else. Sweet as (I recommend a better service regimen however....)
I might also add that the only major Yanmar dealer/service agent I have dealt with a couple of times (elbow, water pump, and advice for a friends motor) were absolutely brilliant (Minards diesel, Newcastle Australia). They even went hunting for my missing pump when Australia Post "mislaid" it, and found it too. Cant recommend highly enough

[ozsailer]

Hello all,
let me re-iterate here. This is a well documented issue with some SD 60 sail drives worldwide. It is not occuring on every drive. The saildrives are not made by Yanmar but another company but are marketed as Yanmar sail drives. A technical paper was sent out by Yanmar to address the one of the possible issues which was improper set up by the installing mechanic and also the gear lever becoming blocked by potruding nuts on the saildrive housing.
It was also acknowledged by Yanmar that there was an issue with the dog clutches not engaging correctly due to a lever inside the unit not being long enough to effect a positive closure each time the gear was engaged ( as in our case)
Yes some operator error as described by Capt Stu was an issue but from my research and personal experience this was far from the case. What surprised me were the amount of "Yanma" qualified mechanics who were not aware of the problem. Although technical bulletins were printed very few made it to the Yanmar mechanics. Every mechanic was surprised when I showed them the paperwork which I printed up for them. Let me advise that coming into a marina in adverse conditions and losing gears at the last moment is not my idea of fun.


Greg H

[Tricolor]

Hi Greg, why not disclose those documents here on CF.? (attachment)

[ozsailer]

Hi Tricolour, with a littel bit of luck here is the Technical notice from Yanmar regarding one of the issues with the SD 60. I have also documented all the issues I experienced to rectify the issues I experienced in the Lagoon 410 forum on this site. Once the clutch assemblies were replaced under warranty we did not experience any furhter issues but we had not run up many hours as well.

SD60_shift_delay 1.pdf


Greg H

[Tricolor]

Hi Greg, this might give the OP a start point to solve his problems. Bad news that not all Yanmar representatives are adequately informed about these issues. Thanks for the upload.

[bermynick]

I just replaced my Yanmar 3JH/SD40's with Nanni 4.40/ Twin Disc sail drives. Some small modifications to the engine bed and new bolt holes for the mounts. Mostly a straight swap.

[pateco]

My Yanmar is over 35 years old, and starts and runs like a champ.

[Cheechako]

Originally Posted by Symphony

bummer to be without an engine on a boat.

other than the crankshaft on the 6LYA-STP (370hp turbo) - it sounds like all the complaints and problems are related to Sail Drive. is this fair?

Well there are some problems, but you will see on line issues with many engines. More people tend to complain about problems than say what's good, and that is pretty natural I guess.
The small GM series have had issues with cracked pistons in the 2GM and 3GM models. I had two in my cat and one 3GM failed under 500 hours and was replaced under warranty. The other failed at roughly 2000 hours with a cracked piston which I had repaired. Some minor things like fuel lines etc.
But generally I wouldn't not buy a boat with a Yanmar. Probably better than some more oddball engines if for no other reason than you can get parts , albeit expensive. Still, they are lightweight engines for their rating, which they get by rating at high rpm in the small engines. But if I was needing engines in the 300 hp and up range I would definitely go with a more commercial use engine.

[Cadence]

I can't understand the Yanmar bashing. Is it running in reverse? Highly unlikely. An old diesel can but. I wouldn't even blame the gear box, it will only do what it is told to do. Find a decent mechanic.
I'd look for satisfaction from Leopard.
Label forward aft and aft forward.