Yanmar exhaust smoke

[Mackaroni]

I had a bit of a hard time starting my engine today, but that isn't too unexpected in that it is cold. However, even after running it at 3000 rpms for a bit, I noticed it seems to be smoking a bit more that I remember. I took a quick video to show. The engine had already been running for 20 minutes or so when I shot this. I ran it at 2000 rpm for a bit and then up to 3000 for this clip.

Is this normal at 3000 or am I burning water or oil? I was hoping it was just crud that had built up from not being run that much, but I ran the engine about 5 days ago as well.

I hope that it isn't anything serious. I don't appear to have any less water in the engine coolant tank and I don't see any difference in oil level (at least that I have noticed.) I ran it all summer and never had to add oil.

 

[Don S/V ILLusion]

Impossible to diagnose without guessing especially as the video didn't load.

Do you consistently run your engine up to 3000 rpm with no load?

You'd know by thebluehaze around you if it was oil. Was it steam/condensation you saw?

 

[jibes138]

I had a bit of a hard time starting my engine today, but that isn't too unexpected in that it is cold. However, even after running it at 3000 rpms for a bit, I noticed it seems to be smoking a bit more that I remember. I took a quick video to show. The engine had already been running for 20 minutes or so when I shot this. I ran it at 2000 rpm for a bit and then up to 3000 for this clip. Is this normal at 3000 or am I burning water or oil? I was hoping it was just crud that had built up from not being run that much, but I ran the engine about 5 days ago as well. I hope that it isn't anything serious. I don't appear to have any less water in the engine coolant tank and I don't see any difference in oil level (at least that I have noticed.) I ran it all summer and never had to add oil.

incomplete combustion would suggest too much fuel in the mixture OR low compression OR air intake blocked/impeded OR a whole variety of other possibilities.

 

[Mackaroni]

Sorry about the video. Try this link

http://youtu.be/wuivR3K7QUk

 

[Mackaroni]

And no, I don't normally run it here without a load, but I was hoping if there was crap in the system, I could blow it out.

 

[centerline]

I had a bit of a hard time starting my engine today, but that isn't too unexpected in that it is cold. However, even after running it at 3000 rpms for a bit, I noticed it seems to be smoking a bit more that I remember.

Probably completely normal...
Cold weather with warm exhaust = steam..

With the hard start you may have had a bit of white smoke on Start up, which could be normal, and as the engine warms up, their may be a bit of steam rising from the wet exhaust....
It wont be as noticable duing warm weather, cuz you wont see the steam...

 

[Don S/V ILLusion]

Steam.

The only thing you might "blow out" doing that is a ring or valve spring.

 

[Ralph Johnstone]

How does it smell ?

 

[Mackaroni]

I was careful not run it very long at those RPM. I didn't smell it.

 

[The Tanqueray]

I was careful not run it very long at those RPM. I didn't smell it.

White smoke represents atomized fuel, very small droplets of fuel that form a fog of sorts. It's common, and quite normal, to see this when a cold engine is started and until it warms up.

 

[RichH]

incomplete combustion would suggest too much fuel in the mixture OR low compression OR air intake blocked/impeded OR a whole variety of other possibilities.

Agree with both Jibes and Tanqueray

Plus, with wintertime temperatures it will take a lot of run-time for the engine to 'heat soak' and come up to design engine temperature (water in the block at 180°F)

Plus, the inlet water to your engine in the Chesapeake is now in the low 40°F range; the Heat exchanger you have is probably designed for what's known as a '15° approach', meaning at 'normal' ambient temperatures (60-70°) the raw cooling water will be 60-70° PLUS 15°± coming out the back end of the boat. The cold 40° raw water is 'over-cooling' the heat exchanger and the engine by about 40° degrees
The air temperature above this 40° bay water is probably close to that 40° and is probably near at 100% humidity (saturated with WATER VAPOR) ...
I'll make the 'bet': Most probably what youre seeing is the formation of LOTS of, or an excessive amount of - WATER VAPOR and unburnt fuel in the exhaust stream discharge ... all due to the cold inlet water (causing excess visible water vapor output), the cold engine (incomplete combustion of the fuel) all being blown out unto the already 'very humid' (probably already close to 'saturated' - 100% humidity) air on top of the already COLD 40° bay water.
This is exactly how clouds and fog are formed.

 

[Mackaroni]

Thank you. You guys have put my mind at ease.

 

[moehorenfeldt]

I would want to check out you water intake, if the engine is raw water cooled. With cold lake water, it wouldn't matter much, but the "smoke" might be steam from a clogged cooling water system. On the Great Lakes we have a problem mid-summer with weeds clogging the system, and one of my friends even had a small baitfish sucked in and the dead fish clogged his water intake. An intake screen is a good investment. My $.02 anyway.