White smoke from exhaust

[foursailing]

I noticed the other day a fair amount of what looked like white smoke coming from the exhaust - appeared like the higher the rev, the greater amount of smoke.

The engine temp was fine and had only been running for a short while.  When I returned to the mooring, I put the boat in neutral and brought it up to about 2200 rpm and could not detect any smoke.

I did notice a similar occurrence a couple of weeks back - after it was running for a while it seemed to go away.

I looked at some related posts which hinted at poor waterflow / intake clogged which is not the case.  Thouhgt it might be related to a fouled prop (end of season / hasn't been cleaned) - but the smoke appears to be white - not black as you might expect with unspent diesel.

Engine has 275 hours.  Any suggestions would be greatly appreciated!

[Larry Robertie]

Gennerally speaking white smoke is from condensation.  That would make sense at the end of the season, or on a lightly used engine.  Not much to worry about, unless you start to see blue or black.

[Ron Hill]

Bill : Just like your auto exhaust in the winter - watch your outside temp/humidity.  When it's low you'll probably see some white exhaust. 

[Wayne]

I noticed smoke about this time last year.  Other guys passed along that if it was white and dissipated quickly it was just steam as a result of hot exhaust mixing with water.  If it was grey or blue, and hung over the water, well that was bad news.

[foursailing]

Great!  Thanks guys, one less thing to worry about.

Bill

[Terry Forshier]

White smoke always meant some water in the fuel. At least it did around here. (Fl hot year round) I would check the filter and see if it is full.

[foursailing]

Thanks Terry - but if water were to get through the filters I think the result would be a lot worse than white smoke from the exhaust?

[Steve S.]

It's really not too much to worry about.  One cause could be that your running the engine to close to top RPM.  The 25's run best at about 80-85% of capacity.  Just ease off the throttle a touch and see if the smoke stops.

[Ron Hill]

Guys : When you run at extremely hi RPM, you should see blue/black smoke coming out of the exhaust.  It's the color of unburnt extra fuel.