Dense black smoke plume - new John Deere diesels

[Richard O]

I am in the late stages of commissioning a new trawler (126,000 lbs. displacement) equipped with dual John Deere 6068SFM-50 diesels; 267 hp. The engines are new - approx 40 hours total.

Propellers are 32” diameter; 24.5” pitch; four blades - and have been used successfully on similarly configured boats.

The engines run well and smokeless in general operation.

BUT, when put into gear and quickly but briefly powered up - for example to generate a brief burst of power during docking - they emit a very, very dense, black plume of smoke from the exhaust.

This has occurred when the engines were hot (after running for a couple of hours, though at low power settings for the 30 minutes or so prior to the docking). It has also occurred with the engines only slightly warm at the dock (an experiment to test for the smoking condition).

The John Deere service center says this is normal and just advises to be less aggressive with throttle action. I fully understand that especially with turbo-charged engines, aggressive throttle action is not desirable. However, this condition was first observed during normal docking operations with a very experienced professional captain at the helm. The throttle action was not abnormal. My prior experience is with CAT-3208 TAs and I’ve never seen anything like this.

I have attached a video showing the smoke plume but beware: it is 2.9 MB.

So, two questions: first, what is the cause of the smoke plume and, second, is it (as the JD tech says) a normal condition?

Any help would be appreciated.

[Landlubber]

As these are electronically controlled engines, there must be a computer malfunction of some sort, there is no way known electronic engines should do this. In fact when ther are abused by the throttle opening, you cannot tell anyhow, as the sensors take over and reduce fuel inputs to suit.

I think that you had better get the JD tech boys onto it. You need the laptop setup to see what has failed and where.

[lazeyjack]

yes are they tier 2?
no modern diesel will do that, even if you are overproped
look at this way, an analogy, a truck, driver to lazy to shift at a hill, buries boot, , there should not be a cloud of smoke at all . Just so happens before I started building boats in 78 i was a field service engineer for Cummins, so I got to know about fueling
Dont be put off you ARE under warrenty, get those people down!! Are you sure they are not Jap diesels black smoke is unburnt fuel, which comes from over fule, or turbos not working, As Lubs says it maybe a engine management electronic issue
Our new design has the 4 cyl tier 2 motor
hey lubs , do you get paid there, cos you sure as heck dont seem to do much work, you a re always here

[FAST FRED]

The John Deere service center says this is normal and just advises to be less aggressive with throttle action.


Deere is probably right , the electronics probably have a bit too much control authority (probably setup for a boat with smaller more rapidly responding props).

No need to worry a few seconds of more fuel than the engine can burn cleanly will do no harm.

I believe DEERE engines ARE Jap industrial marinizations.Not many Mfg of diesels left.


FF

[Richard O]

Thanks for the feedback. The engines are Tier 2 compliant electronic engines - though not single rail.

I don't know whether Deere manufacturers the basic engines or buys others (perhaps Japanese) and marinizes them.

They are under warranty - they're brand new.

But getting useful response from Deere has been nearly impossible. The Deere "authorized service dealer" has been disorganized and careless on the several commissioning issues we've had. On this, they summarily declared it normal - without taking data via laptop, etc. - and moved on. I've again asked (via a web form this time) Deere HQ to provide a live, technically competent person for me to speak with via phone. If anyone has the name and a good phone number for someone at Deere HQ that you feel could be helpful, I'd appreciate the lead.

[lazeyjack]

i think fred is wrong, modern engines do not smoke, full stop, if that were the case every truck, car boat, would, puff black
i do know that deere makes their tractors in India, I will ask my guy here, he is very strait with me
Thats why I like Cummins, their service in next to none