KAD43 blackish smoke at startup?

[A_8]

Got two of the KAD 43's and a few weeks ago I noticed the port one had some blackish smoke at startup, it has not been there before but goes away quite quickly.
I've also noticed the same engine "shudder" every now and then.
The engines are at 650 hours and I am thinking it may be the injectors that needs some attention, injector pump...or could it be the valves?
Anyone have any good advice?
Thanks/
Michael

 

[DavidJ]

Not had the same experience but my first tack would be to put in some fuel additive. This may just unstick a gummed up injector...it can't hurt anyway
best of luck and keep us posted with your problem resolution.

When did you last have the valve clearences checked. It should be every 200 hours although mine (KAD43) had hardly moved a couple of thou

 

[savageseadog]

Not at those low hours. Try the air filter first

 

[volvopaul]

Hate to say this but some of these engines had a bad batch of injection pumps, I had one 2 years ago we could not cure it, swapped pump from another boat engine, new injactors, pump set to 2 different repairers, in the end we had to fit a new pump from volvo, just under 2 k for the pump.

The shudder sounds like a missfire, if its not firing correctly you would see white unburned unatomised fuel, black smoke is usually emitted when the engine is under load and does not have the correct air/fuel ratio mix for a clean burn, though some engines do black smoke more than others.
Does it do this at tickover or when the charger comes in as the revs pick up?.

 

[A_8]

Thanks guys,
I've recently done fuel additives (injector cleaners) and the valves was done at 500 hours, not much adjustment needed. The air filters could be around 100 hours and come to think of it, its been a lot of sea spray this summer because of the very windy weather, perhaps this one is clogged by salt!?

I don't think this would cause the shudder though so I might still have a injector pump issue.


volvopaul,
The shudder is only at tick over and random as far as I can asses, no white smoke that I've noticed.
Possible this engine vibrates a bit more at cruising speeds but its really hard to say as I cant figure out how to test this and be confident of the result.
This issue of bad injector pumps, do you know any specifics, like manufacturing dates or any other commonality that I could look for?

/Michael

 

[volvopaul]

Circa 1993 from memory will find old pump out its in the workshop somewhere.

 

[A_8]

Mine is 2003, seems unlikely to be the same problem!?
Thx/Michael