Northern Lights M673 blowing black smoke

[Michael Black]

My 2001 M673 with 550 hrs is blowing a lot of black smoke and it seems the oil level is high…. Not foamy, could it be diesel fuel in the oil? I changed the oil and the problem continued?

I changed the fuel filters and impeller with no change in the problem – smells and seems hot? and lots of soot in the water. Never had soot before and not sure if hotter than usual – the high temp switch did not shut it down

Could it be a thermostat issue, injection pump issue, coolant pump issue? I cracked the injectors one at a time – all had fuel. I checked the exhaust elbow ( a SS elbow about 3 years old ) completely functional, the heat exchanger tubes are all clear and flowing, water is flowing from the raw water pump. Not sure where else to look?

Thanks in advance for any comments or suggestions.

Topic

[Michael Black]

pictures

Attached are some pictures of the generator…. The last picture is the soot on the water. I ran the generator with the air cleaner out and the top off, no smoke with no load, as soon as I added a load it began to puff black smoke. The filters were crumbling when removed, intact while installed.

Let me know what you think.

Mike

[Michael Black]

thanks Tony. I will get picks tomorrow

As for your other questions, the unit has been extremely trouble free for the time I have owned it, probably the last 300 + hours.. Yes, out of the blue it did this yesterday for the first time. Being winter the unit went unused for about 3 to 4 weeks. Unusual to leave it idle so long, so we decided to run it yesterday.

About 3 years ago I had the unit out of the boat to change to a new raw water pump and new (SS) exhaust elbow, new hoses, hose clamps, and fan belt and other misc maintenance items.

I use the unit for about 4hrs a month + or – a few, running an air conditioner (15 amps) done in 3 increments a month after a fishing trip…. for at least the last 4 years. That is 1 hour or 1.5 hours after a trip, at a time.

I change the oil at least once a year or 100 hours which ever comes first. I change the impeller every year. I change fuel filters about every 6 months.

More with pictures tomorrow.

[Tony Athens]

Michael,

550 Hours, right?

1)———–How did it run at 540 Hours, 530 Hours, 520 hours, Etc etc etc?
I.E. was it running fine, and than just “all of a sudden did this? Your description of what is happening leaves way too much left to the imagination..

2)—-I want to SEE the unit as installed in the vessel..Good pics of all will tell volumes..

3) I know the unit well–It’s typically a 10,000 + hours unit unless it has been totally neglected since it was installed 16+ years ago (Mother Nature and Marine Age never stops doing its thing).

For sure, the unit has not wore out in these hour–Its something about the installation and or zero care since new..

1st test–Remove any air clearer ir connection you have to the intake–let the unit suckc clean un-restricted air..

Post/ Send me good pics of all

Tony

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