How long does diesel fuel last?

Question

I HAVE A BOAT THAT HAS SAT FOR 3 1/2 YEARS. IT IS FILLED WITH DIESEL FUEL. WILL THE FUEL HAVE TURNED TO SLUDGE?; COULD I ADD A CONDITIONER? OR MUST IT BE DRAINED BEFORE TRYING TO START?

Answer 1

I would recommend that you drain the fuel and start with fresh fuel. This article http://www.batterystuff.com/tutorial_fuel_storage.html explains the concepts on storage of fuels (gasoline, diesel, etc.) very well.

Answer 2

Hello,
First let me tell you that I am a yacht mechanic and run into this pretty regularly.It seems as though a lot of yacht owners don't maintain there vessel as they should,they seem to forget about it until they want to use it then they want it ready right away.Enough with the rant.I would suggest that you pump all of the fuel out of the tank or tanks whichever applies.Refill with about a quarter capacity.Then if your boat is equipped with either racor or dahl filters I would replace the elements and hook up an external pump and cycle the fuel for about 2-3 hours on each tank.Then remove the filter elements and inspect them for signs of algae if you see any signs of it add an algae killer like bio-bor or something similar.Replace the elements and repeat until no signs appear.Even if you see no signs I would use a algaecide.
Now depending on which engines you have you may want to repeat this several times before running ie:MAN engines are more particular of their fuel than Detroits.I would make certain that when you store your boat for long periods in the future that you add plenty of bio-bor and even drain the fuel or at least run it once a month or so.I hope this helps.

Answer 3

Unless you poured a LTS additive in the diesel mixture, you probably will not have good fuel in the tank. You'll need to drain it out. There is a wax in diesel fuel that congeals and gums up the engine.

Answer 4

The fuel is man made and will go bad need to drain it and dispose of it properly and refill it with fresh fuel. Good luck Pal.

Answer 5

use it for starting bon fires