Too much soot? Yanmar 6LP-STE

[Norseman]

Doing the 1000 hour service next week and decided to pull and test the injectors:
At max cruise 3600 RPM, clean bottom and clean prop, I smoke a bit, looks like dark grey or brown smoke: Un-burned fuel?
Not over-propped, well maintained boat, etc.
This picture shows my exhaust footprint after about 10 hours of running, half and half max cruise and low cruise.
If this is normal, then I won’t pull, test and overhaul the injectors.
If I am the only one with this kind of soot, the injectors come out next week..

3CA7089F-8B93-430C-AE37-F659CFD6338A.jpeg

Picture was taken in the Gulfstream during a recent Bahamas cruise, had throttled down for the photo op with a sailboater, no smoke right then, but back at 3600 dark smoke, but not heavy like in “Rolling Coal”,
more like transparent brown smoke.

[Tree]

What were your air temps? We had high temperatures here last year and a lot of diesel boats suffered with lack of performance and sooty exhausts - mine also but this did improve much more once I fitted the walker air filter. I suspect I’m due an intercooler clean as I had the injectors done earlier last year. Since splashing this year I’ve seen zero evidence of any spot on the hull or waterline. Air temps at the moment are around 15°c and water around 10°c so I’ll monitor it as the summer approaches.

[Norseman]

Air Temps?
This was about 7-8 weeks ago, about 25-26 degrees.
(We got really nice winters around here, which is why I left Norway )

[Norseman]

. Air temps at the moment are around 15°c and water around 10°c so I’ll monitor it as the summer approaches.

How many hours on motor and on injectors? (Or atomizers as you say in the old country)

[Tree]

. Air temps at the moment are around 15°c and water around 10°c so I’ll monitor it as the summer approaches.

How many hours on motor and on injectors? (Or atomizers as you say in the old country)

I would have been around 1850 hours when I had the Injectors overhauled. They had been previously done at 1300 hours according to the paperwork that came with the boat but I’m not so sure that someone hadn’t just taken a wire brush to them!

[Carl]

So did you clean injectors? Still smoking?

[Nancy's Promise]

I have the same issue. Only when I first start off to get up on plane. I was going to have the injectors done this winter.

[Tree]

I get a little bit of black on initial acceleration before the turbo spoils up - that’s it.

I still get some on the water line after a trip but that is conditions related - if I’m fully loaded in heavy seas but nothing like it used to be prior having injectors serviced and installing the walker air filter.

[RobS]

The intercooler should not be forgotten about.

[jleonard]

An ex boat neighbor had twin Yanmar 170s (4 cylinders). He was getting black smoke on acceleration.
A local Yanmar dealer told him to use a fuel additive with a cetane improver.
He did and the back smoke went away totally.
I am not generally a promoter of additives, but in this case it worked.
YMMV.

[RobS]

Further to Jay's post there was a time when Mack Boring (Yanmar US Distributor) was recommending FPPF's 8+ Cetane Booster

[Tree]

The intercooler should not be forgotten about.

Agreed - I won't be doing that job though as I just don't have the time.

Come to think of it neither does my Yanmar mechanic!

[Tree]

Further to Jay's post there was a time when Mack Boring (Yanmar US Distributor) was recommending FPPF's 8+ Cetane Booster

Thats interesting to know - I use a product called Millers Diesel Ecomax. Smells incredibly sweet. I use it mainly for its lubricating properties as the red diesel here is sulphur free. I read somewhere a while back about lubricating additives being needed on older european engines as the fuel pumps were not designed to be run on sulphur free fuel. I assume US fuel still has the suphur in it or is this not the case?

[jleonard]

[/quote]

I assume US fuel still has the suphur in it or is this not the case?
[/quote]

No. Everything here is ULSD (Ultra Low Sulfur Diesel). Supposedly, the fuel has lubricity additives to bring it to the level where additives are not necessary.
I have not used additives for at least 10 years in either my boat (old Ford-Lehman) or any of the diesel vehicles I have owned (VW Jetta, Dodge-Cummins pickup).

[jleonard]

Further to Jay's post there was a time when Mack Boring (Yanmar US Distributor) was recommending FPPF's 8+ Cetane Booster

Yes that was what he used.