Oil from exhaust?

[Guest]

Common item ...

White smoke at low revs - due to excess air to diesel ratio ...

Black smoke or gunge at high revs - due to excess diesel to air ratio.

Somewhere in between the engine sits nicely !!

The black is usually excess fuel being carboned up in its passage out and of course if it hit's water it will display the distinctive rainbow pattern on water ---- if near or partial burnt - then it will mostly stay black particles on the water ... anyway - you'll get the proverbial black arse syndrome .... ie transom of boat takes on that bespeckled black look !!

All this talk of sumps / valves / pistons etc. - yeh it can be 0 but most times it's as above ....

I'm no mechanic but recognise the symptoms .... now shoot me down !!

/forums/images/graemlins/tongue.gif

 

[oldharry]

Re: Common item ...

Bang...!

.....except I agree - I would start by getting the injectors checked as, if they are worn, damaged or not closing at the correct setting they will be delivering too much fuel, which in turn produces excess soot (carbon) in the exhaust.

 

[Wayward_Son]

All he said was it is a Volvo-Penta 10hp. There is no mention of if it is one of their outboards or inboards or if it is even a diesel at all!

He also hasn't responded since his second post.

More engine information is needed, although all the previous info has been educational (other than the presurized oil pan gaff - what would keep the dipstick from shooting out?).

 

[Ships_Cat]

He also hasn't responded since his second post.

Well if he has been taking notice of some of the posts he is probably very busy off fruitlessly rebuilding his engine or seeking an overdraft to buy a new one based on the advice of some of the posters.

As L'Escargot said at the beginning the most likely cause, unless there are other signs of engine problems, is overloading of the engine through over-propping or hull/prop fouling.

That is the most common cause of black slicked exhaust for a wet exhaust system if it only occurs under load, and unless a boat is under-propped most pleasure boats with small engines can be made to do it. If one does not believe that then while berthed, so ones own boat cannot move, run the engine, put in gear and put the throttle full ahead and observe what happens to the exhaust - all assuming a diesel, of course.

John

 

[jake44]

Sorry not to reply (been away but not rebuilding engine!)

The engine is inboard deisel approx 5 years old (light use) in 23ft Virgo Voyager.

Looks like I should take advice of L'escargot & others and perhaps get it checked out by a mechanic.

Thanks to all who advised

Jack

 

[geoff]

Had the same on my 10hp penta...frightened the life out of me until I looked at the emergency stop lever...it was partly out...stuck it back in again...right as ninepence, hope yours is a simple as that