Black soot out my exhaust

[jimi]

If i run my engine at full bung I getr black sooty water coming out the exhaust .. is this nbecause I'm carrying the marine equivalent of a rain forest around on my bottom causing unburnt deisel or is it an engine issue , its a Yanmar 3GM

 

[Danny Jo]

Conventional explanation is "you're overpropped, mate". Removing the rainforest will increase your speed, but my guess is it won't change the sooty exhaust at full revs.

However, unless you have a variable pitch prop, it is arguably better for a sailing vessel to be overpropped than underpropped, because motorsailing will be more economical, provided you are not thrashing the engine.

 

[MarkG]

But Jimi didn't say the rainforest was on his boat, he said it was on his bottom..

as for the sooty exhaust - it just needs a good sweep....ho ho ..

 

[Dalliance]

It's worth checking that you haven't got something fouled on the prop our that it's got a particulalry bad weed growth.

 

[brianrunyard]

The rain forest is holding you back and putting extra load on the engine preventing it from running efficiently and therefore causing unburnt fuel, are you also getting black smoke?

 

[jimi]

Yes, I'm also getting black smoke at full throttle

 

[brianrunyard]

Engine is overloaded, cleaning the bottom will probably cure it.

 

[zyx]

Engine clapped out, how many hours has it done?

 

[jimi]

hope not .. 1000 hours

 

[Sailfree]

May be worth posting on PBO as many engine experts on there where they may only dip into this Forum occassionally.

In fact look at buying first boat - smoking exhaust on PBO
If you have a dirty bum you should be sailing slower as well!

If you are sailing as fast but only motoring more slowly and smoking its either a problem with the engine or prop.

 

[ParaHandy]

i'd lay ma siller oan ra exhaust elbow being bunged up ... which would make it the second yanmar youse haud yer paws oan (well, nearly) with this ... nae santa coming doon yer lum ...

 

[chrishelen]

Have you cleaned your filters?