Ad41 1988 unburnt fuel issue.

[standfirmrasta]

My question, is it possible to adjust my fuel pump so as to avoid distributing unburnt fuel into the environment and all over the back of my boat and tender?
I wondered as this is a 1988 piece of kit that it would be manually adjustable, I have had the injectors serviced to no avail.
Any advice appreciated.

 

[[2068]]

I don't think the fuel pump is the place to start.
Instead, I'd be thinking about getting enough air in there.

So
... crankcase breathers?
... air filters?
... aftercooler clear?

Also, is it getting up to the correct temperature?

Even when everything is 100% these engines are a bit smoky.

 

[NormanB]

+ 1 and in addition that there are no impediments in the exhaust manifold and downstream system. Poor scavenging can be a combination of sub par inlet and exhaust conditions.

 

[volvopaul]

My question, is it possible to adjust my fuel pump so as to avoid distributing unburnt fuel into the environment and all over the back of my boat and tender?
I wondered as this is a 1988 piece of kit that it would be manually adjustable, I have had the injectors serviced to no avail.
Any advice appreciated.

You won't stop an old 41 A from smoking , it's compression ratio is low which means at idle speed when co ld the ratio of fuel to air dictates this.

 

[QBhoy]

Get the injectors overhauled. They will likely be weeping.
From memory, they are meant to be done every 500hours, if not 1000. Sure it's 500 though.
Chances are, they will be weeping.

 

[Mike scott]

Spent a fortune trying to cure my ad41a from smoking . Replaced pumps injectors in fact everything. Still smoked on startup. Some still have exhaust brakes still fitted but we're so problematic most people removed them. Reliable but smokey .

 

[oldgit]

One particular vessel in our club, a Corniche 31 with a pair of AD 41, has start up smoke that a fleet of destroyers would be proud of.
However after about 20 mins the marina visibility is OK for the rest of the club boats to move about in reasonable safety.
In any decent gale it does clear faster.

 

[standfirmrasta]

Mine actually don't smoke very much at all, what concerns me is the amount of unburnt fuel that is escaping out the back of the boat, for instance when under load ie going up the back of swell I have clouds of brown haze emitting from the rear :-(
I am not aware of any air starvation all filters etc new and OK which is why I have come here for some learned advice

 

[Neilthesparky]

One of my aqad41a's used to suffer lots of black smoke on acceleration and less when up and planing, also had a bit of performance issues, turned out that the full load fuel pin that activates as boost increases stuck in the full load setting which gave blackish smoke when running, fuel injection pump specialist sorted it out for me, still get black smoke when getting up on plane but none when cruising along. It located under the cap in your third picture

 

[dsw]

some thing in the pump is sticking or worn . also have you checked the leak off return system ?

 

[standfirmrasta]

Next job to check the return system ....forgot to mention both engines run like a dream

 

[superheat6k]

Next job to check the return system ....forgot to mention both engines run like a dream

You mention the engines work like a dream, if me I would definitely not mess with the fuel pumps. You could get them check calibrated by a firm like Poole Diesels. The governor should also be checked at the same time, or simply put up with it and clean the transom when necessary.