Diesel Fuel additives

mattinri

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I'm going to do my first refuel on the new boat (Cummins QSB 5.9). Do I add any additives when I refuel? I used Startron in my old gas engine & noticed they have a diesel formula. Not sure what to do with the diesel...
 

Blitzen

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Matt,

Proceed with caution, if you use a biocide be prepared to be changing a lot of filters, if the previous owner has not been treating the fuel it could be full of algee and when the biocid kills it, it will plug up the system. If you can confirm that it has been treated than I would use Howes or Marval Mystery Oil. Otherwise use BioBore and get ready.
 

Beamie

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Lets understand something here. The bugs, "algea" live in the fuel water interface. Not in the fuel. Thinking about this if you have water in your tank and it is below your pick up then your not going to have a problem. If you already have bugs and you have enough water to get in your pick up them you are going to have problems whether you using biocide or not. If your not using biocide and have issues it is too late. Use the biocide as a preventive measure. It is designed to stay at the bottom of the tank in the water fuel interface to kill the bugs. If you have algea and use biocide yes you may go thru some filters, this will go away with time. After that you shouldn't have issues.

Second, if you happen to know the fuel is Ultra Low Sulfer dielsel, you should add a lubricity additive. We are talking sulfer levels below 0.1% sulfer. I have seen ULSD be 0.0009% sulfer. If you can't find any commercial products in small quantities put a quart of Mystery oil in your tank.
Sulfer is a lubricant. Having none takes its toll on fuel pumps and injectors.
 
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CEShawn

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I've got some good pictures I need to post here...

The mainstay of the bugs, is more the POOP, that is what clogs the filters, so kill the bugs before they POOP... Less problem
 

Blitzen

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I've got some good pictures I need to post here...

The mainstay of the bugs, is more the POOP, that is what clogs the filters, so kill the bugs before they POOP... Less problem


Than what could have been creating a sponge like material to be growing in the fuel lines of my old lobster boat?
When I pulled apart the fuel system to my surprise I foung a perfectly round tube of growth from the tank to the filter. Hard to believe but the boat would sit for long periods of time when I was on the ship and I believe heat humidity and the fuels natural ability of being hygroscopic caused my problems. The fuel will have moisture in it saturated or unsaturated and stuff will grow given the right conditions.
 

CEShawn

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I was a on sea trial last month, and boom lights out... Fuel came in great, no water, etc. However tank was perfectly clean, water was there, bugs came next over a month period or so, not exactly sure. I was only onboard more as a consultant. Guess what, no dosing, no fuel treatment, etc...

That saturation is a great statement...This is then 24 hours later after it was "clear and bright" as taken. Definitely had more than one issue here, believe the water was more of a problem than the bugs though at this point.

P8060048.jpg

P8060051.jpg

P8050031.jpg
 

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