2 Year Old Diesel Fuel in Tanks

[endoftheroad]

I just bought a boat that has 70 gals fuel capacity.
The tanks are about half full.
The boat has been on the hard for 2 years and the motor hasn't been run since motoring into the travel lift.
There was some fuel stabilizer added 2 years ago.
I drained the condensation from the fuel, there was about 1 pint of water.
The racor filter was full of Algae.
The filter on the motor was clean.

Is the fuel still ok?
Should the fuel be removed from tanks and replaced with fresh?

Thanks

[Tellie]

Originally Posted by endoftheroad

I just bought a boat that has 70 gals fuel capacity.
The tanks are about half full.
The boat has been on the hard for 2 years and the motor hasn't been run since motoring into the travel lift.
There was some fuel stabilizer added 2 years ago.
I drained the condensation from the fuel, there was about 1 pint of water.
The racor filter was full of Algae.
The filter on the motor was clean.

Is the fuel still ok?
Should the fuel be removed from tanks and replaced with fresh?

Thanks

Every now and then this subject comes up and you'll get different opinions. But it's only 35 gallons. Start with fresh fuel and eliminate that doubt when re-commisioning the engine.

[David M]

If it is only 35 gallons I would pay to have it hauled off. Now that your tank is empty you can open the access port(s) and wipe out what sediment you can reach.

Start with all new filters, run your engine for a few hours and then change your filters again. The chances then of clogging your filters anytime soon are pretty minimal. Any solids in your fuel system by then should be pretty well flushed through. Then shock treat your fuel system with a biocide and then use the prescribed about of biocide each time you fuel.

[roverhi]

Diesel does not get stale nearly as quickly as gasoline. It can go many years and still work fine. I'd expect you won't have a problem with the fuel in the tanks. The big problem is if the fuel has grown a bunch of bacteria. Monitoring the fuel filter will tell you if it is beyond useful life. When you say fuel stabilizer, was that a biocide or just an additive to stop evaporation of the lower flash point components??

Make sure the tanks don't have pinhole leaks. It's a common problem with Westsail fuel tanks if they've been sitting water.

[Bash]

congratulations on the new boat!

I'd be tempted to have the fuel polished, if that service is available in your area. Consider it an opportunity to start off with a sediment-free fuel tank.

[endoftheroad]

Originally Posted by roverhi

Diesel does not get stale nearly as quickly as gasoline. It can go many years and still work fine. I'd expect you won't have a problem with the fuel in the tanks. The big problem is if the fuel has grown a bunch of bacteria. Monitoring the fuel filter will tell you if it is beyond useful life. When you say fuel stabilizer, was that a biocide or just an additive to stop evaporation of the lower flash point components??

Make sure the tanks don't have pinhole leaks. It's a common problem with Westsail fuel tanks if they've been sitting water.

Thanks everyone for the help.

Roverhi, The previous owner just said he added "some conditioner".

[SabreKai]

I just purchased two stainless tanks that came out of an old 1950s built cabin cruiser. Both tanks are about 60 gallons and full.

I purchased two 210 liter drums from a refurbisher for $25 bucks a piece. I am going to empty them out with pump and filter I'm putting together at the moment. As far as I know the fuel is at least 3-4 years old. However I have had several inquires to purchase the fuel. I figure once its been filtered it should be good. I'm going to run it through a Racor 10micron filter just to get it out of the tanks and then refilter with a 3 micron filter if I use it myself. I figure on selling about half of it. I agree, diesel doesn't go stale for a goodly amount of time because most of the volatiles are removed in the cracking process. Diesel is made from the oil after gasoline has been removed.

[2007.pierre]

The problem with old Diesel start with the first question: Did you buy the boat with a certain amount of Diesel stock? If yes, the next question is: are the prefilter and final filter dirty? If yes, you may find that you have no problem if you navigate in intra coastal waters or relatively calm seas. When you face a storm and you need the engine, at that moment the engine may starve as all dirt and algea are well mixted in the fuel and quickly clogg the filters. The best and easy is when on dry dock, transfer the total amount of fuel to a barrel, clean the tank and put it back using a pump and a prefilter. Then add some conditionner and top the tank. This way you should have no problems for years, adding a small quantity of conditionner yearly.
It is whise to install, before the prefilter, a decanter with a glass bowl that will collect any water and signal the presence of algea.
On the boats I had, every year I always add one gallon of petrol and one quart of denatured alchool to absorb water condensate.

[TEE]

If you have algae in the tanks, and two year old fuel, get rid of the fuel first, then clean the tanks. If you don't, you will never get rid of the problem. If you get out pn the water, and add a bunch of biocide to old fuel, you will never know when and if you filters will clog and shut down your engine, but I think it will happen at the worst possible moment. If you absolutely don't want to dispose of the fuel, at least get the fuel polished by a professional before adding any more fuel, add a bunch of biocide, and buy a case of racors before you set out. When you get in rough seas, the green having died and turned black will break off in the tank, clog the fuel line or filter and kill your engine. I tried doing it the "easy" way a few years back and had a fuel system perpetually haunted by demons and filters clogged by what looked like black rubbery goo.

[s/v Jedi]

My diesel is more than 4 years old now. Diesel doesn't expire, why pay to get rid of expensive fuel ?!

Get a clean plastic drum and transfer your fuel in it through a baja filter or similar and add amount of StarTron enzyme based biocide for initial treatment. Then clean tanks and transfer fuel back through baja ilter again.

ciao!
Nick.

[CSY Man]

You should not have any problems:
I know guys/amateurs running their engine on 20 year old diesel.
(Florida, not Alaska)

keep a good filter and go sailing.

[mrohr]

Pay to get rid of diesel ? Pump it out and burn it in your home furnace,works fine for me.

Congrats, you have just turned a liability into an asset.

[endoftheroad]

Thanks for all the info.....
I bled the lines and the motor purrs nicely.
I added fresh fuel and starbrite.
I will keep in mind all the advice and be as ready as can be for trouble.

Thanks

[DeepFrz]

+1 on what Jedi says. You need to filter the fuel and clean the tanks. Personally I would prefer to run it through a racor fuel filter rather than the baja filter. Just my opinion.

[s/v Jedi]

Originally Posted by DeepFrz

+1 on what Jedi says. You need to filter the fuel and clean the tanks. Personally I would prefer to run it through a racor fuel filter rather than the baja filter. Just my opinion.

It's a W32... baja filter crowd

ciao!
Nick.