volvo black exhaust

[alf1]

just reading a post about black smoke from a yanmar I have a similar problem with a volvo 2001. I cleaned out the exhaust elbow.Is this the same problem and do i need a exhaust elbow.a couple of times it would not turn over on starting.no black smoke in neutral only in gear forward or astern

 

[wotayottie]

the throttle on a diesel controls the injectors, so when you open the throttle more diesel is squirted into the engine. but the air flow is controlled by the engine speed, so if the engine isnt turning over fast enough for the amount of diesel that is being squirted in, you get unburnt diesel coming out of the exhaust as black smoke.

your symptoms suggest that there is something stopping the engine turning fast enough when it is in gear. that could be anything from a rope round the shaft to the wrong size of prop to less likely problems like a seized bearing in the gearbox.

dont see why the exhaust elbow would be a problem if it is clear. a blockage in the exhaust pipe might cause black smoke. but most likely is something round the prop.

if the drag is great enough it would make the engine difficult to start.

 

[alf1]

I have just been out of the water to antifoul all clear

 

[FlorealIII]

Is the timing of the diesel pump correct ?

 

[alf1]

spot on did it 5 years ago been fine recheck it last week