Yanmar Oil leak on 4JH4

Hi tbbmarine,

OK, nice to hear that the information has been helpfull.

The sealing is something like a rubber ring which has a metal feather inside which tightens the rubber arround the axis. We call it a simmerring which is explained at http://www.eriks.nl/index.php?dynamischeafdichtin .

Once you know this, two issues might be the cause of your leak. 1. The feather is broken, 2. the rubber is broken somewhere in the area where it meets the axis.

In the first case, I do not really know when and how things will get worse. In the second case, I would not give it a try. It might very well be the case that the ring will be ripped in parts quite quick which causes a greater leak.

In my case, I was under warranty, but discussed things with a dealer in Denmark, one in Holland and Yanmar Benelux. They all adviced me to have it replaced just to prevent that its the broken rubber (case 2) you're dealing with. In Denmark they gave me some spare oil and advised me to check frequently. I made another 70 hrs. before I was back home where they replaced it and things did not get worse in the meantime.

So if you like to wait, check frequently and, in my personal opinion, it wont be the case that the SD will blow all the oil out at once, meaning, it can come to 10 drops or 30 drops an hour from one moment to the other, but then you will notice this during your frequent check. The problem then is, that you have to repair which might be during holidays or a moment that doesn't fit you. I think the bottom line is that you have to do it anyway.

Now, regarding taking out the engine, right from the beginning, I had the same feeling as you have. I had the advantage that a Yanmar Dealer had to do the job under warranty so my concern was taken down to the proportions of chosing the right one. You know, one with mechanics who also know something about boats and wo would be able to take down parts of the interior without damaging. I found them, they exist.

What they did, they took out the wooden panels around the engine. Wow, that realy put things in another daylight! Then they can realy and easily work on the engine. They made a kind of gliding construction, from wood, put it under the engine, dismounted everything, and glided the engine to the front (somewhere to the entrance of the toilet).

After replacing the sealing, they mounted everything back again. No more than 2 days work!

So far, all the best for you, greetings, Willem Bürmann

I was slightly shocked to see that a 411 dismasted on the first race of the Hanse Cup this year (end of August). The boat is Brunella -