djmarchand
Captain
- Joined
- Jul 24, 2012
- Posts
- 664
- Likes
- 295
- Location
- Litchfield, CT / Punta Gorda, Fl
- Boat Make
- Atlas Pompano 23 outboard
I am an avid follower of the boatdiesel.com forum and a sometimes poster. I was recently struck by the following scenario that plays out time after time on that forum, often once a week:
1. Someone posts that his engine seems down on power, isn't getting up to wot rpm, blows black smoke, etc.
2. Tony Athens, the Cummins/Yanmar moderator, posts a response asking for pics of the engine installation.
3. The OP hems and haws but finally posts the pics requested.
4. Tony then asks the OP to remove the exhaust elbow and take pictures of the exhaust turbo outlet.
5. The OP posts the pictures.
6. Tony and others tell him that he has been getting seawater in his turbo, it is trashed and he needs to replace it, but first he needs to redesign his exhaust system so it doesn't keep happening.
It seems that our DE boats are prone to this happening, particularly those without an engine box. A flat deck almost assures that there is not enough height for a properly designed system. A minimum of 12" is recommended; see the attached drawing, courtesy of Tony.
But I don't hear too much about this problem on this site. So what happens. Do owners simply replace the turbo every 2-3 years and consider that a price of doing business. Do owners just live with low turbo performance and low power in between replacements. Or is there something about every day commercial use that keeps it from happening. Almost all of the cases on boatdiesel are recreational owners. Or do we just not talk about this problem.
I wonder?
David

1. Someone posts that his engine seems down on power, isn't getting up to wot rpm, blows black smoke, etc.
2. Tony Athens, the Cummins/Yanmar moderator, posts a response asking for pics of the engine installation.
3. The OP hems and haws but finally posts the pics requested.
4. Tony then asks the OP to remove the exhaust elbow and take pictures of the exhaust turbo outlet.
5. The OP posts the pictures.
6. Tony and others tell him that he has been getting seawater in his turbo, it is trashed and he needs to replace it, but first he needs to redesign his exhaust system so it doesn't keep happening.
It seems that our DE boats are prone to this happening, particularly those without an engine box. A flat deck almost assures that there is not enough height for a properly designed system. A minimum of 12" is recommended; see the attached drawing, courtesy of Tony.
But I don't hear too much about this problem on this site. So what happens. Do owners simply replace the turbo every 2-3 years and consider that a price of doing business. Do owners just live with low turbo performance and low power in between replacements. Or is there something about every day commercial use that keeps it from happening. Almost all of the cases on boatdiesel are recreational owners. Or do we just not talk about this problem.
I wonder?
David
