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Old 17-02-2014, 07:56   #1
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black smoke underload

I noticed that when running my diesel 2 cyl. under heavy load I get black smoke, throttling back it seems to clear,
can a dirty prop and hull cause this, I was also going to add a fuel injector cleaner,
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Old 17-02-2014, 08:03   #2
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Re: black smoke underload

Black smoke indicates a heavy load on the engine like a diesel electric train pulling out of the station. A foul bottom or over propping can cause it
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Old 17-02-2014, 08:13   #3
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Re: black smoke underload

Some causes in rough order of likely hood: fouled bottom, fouled prop, plugged exhaust water injection elbow (mostly Yanmars), too much prop pitch, air cleaner plugged, not enough vents in engine room.

Check the inexpensive stuff first: clean your bottom and prop, open the engine room termporarily, check air cleaner, pull off water hose and look inside for fouling, etc.

David
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Old 17-02-2014, 08:19   #4
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Re: black smoke underload

the engine starts and runs good. I use bio in the fuel and keep clean filters. it has good flow from exhaust. I plan on getting bottom cleaned, how about adding a injector cleaner,
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Old 17-02-2014, 08:21   #5
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Re: black smoke underload

from a more serious standpoint....
yes whenever i asked about the increasing black smoke from my exhaust, i was told these same lies.
black smoke is a fuel delivery system problem exhibited gradually more each use until it fails....

is your engines song uniform and even. if there is a glitch or variance in song, check injectors and fuel injector pump.
if you have black fuel returning to your tank from return hose, have your lift pump checked. make sure that the electric assist pump is turned off for running.
if you have extra oil in your crankcase check lift pump.
have fuel delivery system troubleshot by a mechanic specializing in the fuel delivery aspect of diesel engines.could save you a runaway such as i experienced.
best of good fortune

oh yeah i am only a gurl how would i know anything..rodlmffao....
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Old 17-02-2014, 08:35   #6
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Re: black smoke underload

Quote:
Originally Posted by zeehag View Post
from a more serious standpoint....
yes whenever i asked about the increasing black smoke from my exhaust, i was told these same lies.
black smoke is a fuel delivery system problem exhibited gradually more each use until it fails....
You are right but you are also wrong:

On a normally running engine the exhaust should be clear and no smoke seen at all and so any smoke indicates a potential problem. Black smoke is the most common, and it indicates that unburned fuel is being ejected with the exhaust gases. This can result from clogged injectors causing fuel to not atomize correctly and hence not burn. If this is the cause then the injectors will have to be removed and serviced by a company specializing in this work as, once disassembled, they have to be rebuilt to precise standards and then set to a correct opening pressure. But most often black smoke is a result of a badly fouled prop or boat bottom. If either of these put excessive load on the engine the injector pump will deliver maximum fuel to the engine but because of the load the engine will be turning slowly and will not be able to use all the fuel.

Diesel engines: repair and maintenance

From personal experience; I have seen diesels emit black smoke while running in gear at the dock with an improperly pitched feathering prop. Once the pitch was corrected (by me), the black smoke disappeared.
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Old 17-02-2014, 08:39   #7
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Re: black smoke underload

and where am i wrong, considering i posted EXACTLY that which has been EXPERIENCED not that which came from wikilyingpedia.
shake the nitrogen bubbles out of your ears and tell others they are wrong. be real.
i am in real world EXPERIENCING these ACTUALITIES.

oh yes....what you quoted backs up exactly what i said... lose your chip on your shoulder and respond more appropriately.
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Old 17-02-2014, 08:43   #8
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Re: black smoke underload

Quote:
Originally Posted by zeehag View Post
and where am i wrong, considering i posted EXACTLY that which has been EXPERIENCED not that which came from wikilyingpedia.
shake the nitrogen bubbles out of your ears and tell others they are wrong. be real.
i am in real world EXPERIENCING these ACTUALITIES.

oh yes....what you quoted backs up exactly what i said... lose your chip on your shoulder and respond more appropriately.
Talk about chips on shoulders.

However, if I misundertood your statement that posters claiming that a fouled bottom or a fouled/poorly pitched prop could be the cause of black smoke were incorrect or lying, I apologize.
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Old 17-02-2014, 08:46   #9
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Re: black smoke underload

Zee, thousands of people have experienced black smoke. You are not the first. The summary by fstbtms has the most likely causes. Until the simple things are eliminated no need to look for some esoteric fault. Your experience is a one off. While not technically "wrong" it doesn't mean yours is the only possible scenario. The OP needs to check the basic things before pulling the injectors and pump.

IMHO It is rude to suggest that the other posts in the thread are lies. They are in fact not lies.
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Old 17-02-2014, 08:52   #10
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Re: black smoke underload

WHEN one describes a scenario that happens and not just to my own boat, otherwise i would not have MENTIONED this... this has happened to 3 boats including my own in the past 8 months.
exactly as i described..but mine added the excessive spew of carbony oily contents of exhaust into ocean at half way point into a 200 mile passage uphill. alleged mechanic reports.."oh, btw, we had black return fuel in zihuatenejo..." lovely....
when i report a situation or happening and someone has to immediately try to rule my words as wrong, THAT my dear, is a chip on shoulder. please remove it and behave as would a proper gentleman.
this lady knows a lot more than even you do. appreciate and relax.

what fatbottoms posted was book backup to my description. if you had read my words precisely as written you too would know and understand that black smoke is fuel delivery problem. what comprises fuel delivery..rofdlmffao...
.fuel injector pump,lift pump, electric assist pump, and injectors as well as the cute lil coppery tubies the fuel passes thru and also copper washers and banjo fittings. and fuel tank. dont forget return hose and fill hoses.

but then i dont know anything i just used to rebuild my own engines and systems in my older cars before i bought boats.
rodlmffao yet again.
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Old 17-02-2014, 08:58   #11
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Re: black smoke underload

Quote:
Originally Posted by zeehag View Post
appreciate and relax.
Oh, I am quite relaxed. That you felt attacked by me when no such attack ocurred is indicative of your state of mind, however.

Since you clearly missed the intent of my previous post, I'll lay it out for you:

You were correct in stating that black smoke is indicative of a fuel delivery problem. You were incorrect in stating that this fuel delivery problem could not be caused by a foul bottom or prop.
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Old 17-02-2014, 09:01   #12
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Re: black smoke underload

there was no need to post that i am allegedly wrong then post in book terms EXACTLY that which i posted. next time i will save you grief and report your rudeness. thankyou.

and i am aware that many experience black smoke. all i stated was that it is a fuel delivery problem and mentioned a nice example of extreme fuel system fail.
some folks actually trouble shoot their failing systems before extreme fail happens. if they do not then they find my words are dead on.
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Old 17-02-2014, 09:03   #13
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Re: black smoke underload

Quote:
Originally Posted by zeehag View Post
there was no need to post that i am allegedly wrong then post in book terms EXACTLY that which i posted. next time i will save you grief and report your rudeness. thankyou.
Oh brother.
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Old 17-02-2014, 09:05   #14
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Re: black smoke underload

RODLMFFAO
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Old 17-02-2014, 09:47   #15
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Re: black smoke underload

> Black smoke indicates a heavy load on the engine like a diesel electric train pulling out of the station. A foul bottom or over propping can cause it
...
> Some causes in rough order of likely hood: fouled bottom, fouled prop, plugged exhaust water injection elbow (mostly Yanmars), too much prop pitch, air cleaner plugged, not enough vents in engine room.


Quote:
Originally Posted by zeehag View Post
from a more serious standpoint....
yes whenever i asked about the increasing black smoke from my exhaust, i was told these same lies.
Care to enlighten us on which of the above are "lies"? i.e are not potential causes of black smoke?
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