I'll be starting my diesel after more than a couple of years of it being idle. My question is should I empty my fuel tank and put fresh stuff in or is old diesel ok to use after it's a been sitting in the fuel tank for a few years?
I don't believe the diesel itself has a shelf life....but the bugs that can grow in it, and the water that may get in, are another matter. If it has been treated with a bio treatment in could be ok.
It really depends on how much diesel in the tank and weather the take is full are near empty... 100L or so - dump it.
1000L or so worth a test...get 3 or 4 or more new filters (you always need them). fit new filter, and disconnect fuel line from engine and just run the fuel line after filters into a jerry can.
check after 5/10 minutes for stuff in filter or water, if there is give up, and dump the lot it will get worse.
Other wise continue....but go to the bottom that is where the nasty stuff is.
Assuming you have a glass fuel filter between fuel tank and engine use a torch to inspect the fuel in it and make sure its clear. if it is you are looking good. Decompress engine and hand crank it to get it lubricated and to check it. After you start up check the filter a few times thats it clear. i think many of us motor around with 2 year old fuel. im using the same fuel i filled up with 2 years ago. i agree wirh previous suggestions, it can get contaminated and if so its no good. That happened to me and to be stingy i got a Supacheap auto 12V fuel pump and put it inline with 2 CAV fuel filters sucking fuel out of bottom of tank and feeding it back in top. 2 days later beautiful! Then i lent boat to a mate who accidentally put petrol in it !!! That took weeks to fix.
Select to expand quoteclaverton said..
I'll be starting my diesel after more than a couple of years of it being idle. My question is should I empty my fuel tank and put fresh stuff in or is old diesel ok to use after it's a been sitting in the fuel tank for a few years?
It's only 40 litres in your case and I would suck it out and give away or keep for cleaning purposes etc. Suck it out from the bottom with an electric sump pump.
Select to expand quoteRamona said..claverton said..
I'll be starting my diesel after more than a couple of years of it being idle. My question is should I empty my fuel tank and put fresh stuff in or is old diesel ok to use after it's a been sitting in the fuel tank for a few years?
It's only 40 litres in your case and I would suck it out and give away or keep for cleaning purposes etc. Suck it out from the bottom with an electric sump pump.
Cleaning purposes.... whats that Ramona, that's a use I haven't heard of?
When I bought Alibi I ran the fuel in the boat and jerry through before thinking.
It was at least 6 years old and no problem.
Wouldn't do it again though! 
Cheers
Bristol
How far do you want to go with this? Here's photos of my new boat's filter and water bowl. Given I planned to take it into open waters, I'd already intended to remove and clean the tank. There was 2-3cm of sticky, foul smelling tar in bottom of the tank and outside of the intake pipe. Because of baffles in the tank it'd have needed a steam clean and pressure test even to see if further work was needed. It was cheaper to replace it with a Diablo tank.
For all this, the engine had been starting and running fine. Local tank bloke reckoned this was because it was a small diesel and didn't suck hard from the tank... but after a bit of rough weather it would have been a different story. The motor filter was fine. I replaced all filters, diesel, cleaned the CAV housing, added a bulb pump near the tank, added 10 litres of new diesel with algae shock treatment, and all's sweet, plus now I can see what's in the diesel.
Select to expand quoteTrek said..
Cleaning purposes.... whats that Ramona, that's a use I haven't heard of?
Diesel fuel is quite useful for cleaning engine parts.
Early submariners bathed with it before going on shore leave due to the impossibility of having enough fresh water on a submarine for bathing purposes.
Select to expand quotecisco said..Trek said..
Cleaning purposes.... whats that Ramona, that's a use I haven't heard of?
Diesel fuel is quite useful for cleaning engine parts.
Early submariners bathed with it before going on shore leave due to the impossibility of having enough fresh water on a submarine for bathing purposes.
Even lubrication and in a tight spot as a rust and penetrating oil
Mu old Bukh had the secondary filter much the same as Bush Dogs the Bukh had been serviced regularly I was told maybe the
Cav filter was but the Bukh filter bolted to the engine looked to be 37 years old 
.
Probably because in my old boat you have to lay on the stern bunk and work between the cockpit floor and the stern bunk which would be less than 300mm makes it hard for the best of us and much worst when your on the autumn of life.
I removed one of the stern bunks now I have all the room I need laying on the bare hull and can lay in there for hours on a cushion. I cant for the life of me think that Id have more than couple of people sleeping on the boat at one time.
I'm moving the manual bilge pump some time soon as that sort of in my way when working side on the motor
My priorities are good rigging good sails good reliable motor and good anchor plus some instruments along the way.
ill finish the anchor system in the coming months and basic interior and keep working on her
Select to expand quotecisco said..Trek said..
Cleaning purposes.... whats that Ramona, that's a use I haven't heard of?
Diesel fuel is quite useful for cleaning engine parts.
Early submariners bathed with it before going on shore leave due to the impossibility of having enough fresh water on a submarine for bathing purposes.
That was to keep the crabs off the boat Cisco . Are you being polite
Select to expand quoteHG02 said..cisco said..Trek said..
Cleaning purposes.... whats that Ramona, that's a use I haven't heard of?
Diesel fuel is quite useful for cleaning engine parts.
Early submariners bathed with it before going on shore leave due to the impossibility of having enough fresh water on a submarine for bathing purposes.
Even lubrication and in a tight spot as a rust and penetrating oil
Mu old Bukh had the secondary filter much the same as Bush Dogs the Bukh had been serviced regularly I was told maybe the
Cav filter was but the Bukh filter bolted to the engine looked to be 37 years old .
Probably because in my old boat you have to lay on the stern bunk and work between the cockpit floor and the stern bunk which would be less than 300mm makes it hard for the best of us and much worst when your on the autumn of life.
I removed one of the stern bunks now I have all the room I need laying on the bare hull and can lay in there for hours on a cushion. I cant for the life of me think that Id have more than couple of people sleeping on the boat at one time.
I'm moving the manual bilge pump some time soon as that sort of in my way when working side on the motor
My priorities are good rigging good sails good reliable motor and good anchor plus some instruments along the way.
ill finish the anchor system in the coming months and basic interior and keep working on her
You should carpet your engine room H20 it would be nice to lay on while tinkering with your Bukh or perhaps reading a book!
Select to expand quotesouthace said..HG02 said..cisco said..Trek said..
Cleaning purposes.... whats that Ramona, that's a use I haven't heard of?
Diesel fuel is quite useful for cleaning engine parts.
Early submariners bathed with it before going on shore leave due to the impossibility of having enough fresh water on a submarine for bathing purposes.
Even lubrication and in a tight spot as a rust and penetrating oil
Mu old Bukh had the secondary filter much the same as Bush Dogs the Bukh had been serviced regularly I was told maybe the
Cav filter was but the Bukh filter bolted to the engine looked to be 37 years old .
Probably because in my old boat you have to lay on the stern bunk and work between the cockpit floor and the stern bunk which would be less than 300mm makes it hard for the best of us and much worst when your on the autumn of life.
I removed one of the stern bunks now I have all the room I need laying on the bare hull and can lay in there for hours on a cushion. I cant for the life of me think that Id have more than couple of people sleeping on the boat at one time.
I'm moving the manual bilge pump some time soon as that sort of in my way when working side on the motor
My priorities are good rigging good sails good reliable motor and good anchor plus some instruments along the way.
ill finish the anchor system in the coming months and basic interior and keep working on her
You should carpet your engine room H20 it would be nice to lay on while tinkering with your Bukh or perhaps reading a book!
Once my chaos is gone I will South Ace . At the moment for me to do some thing on that piece of 28 foot I have to move some of it before I start. Tomorrow I think I will put as much as I can in the car and bring it back here.
Then just finish off from the stern and work forward that's what I've been doing the last week or so.
Tomorrow id bilge pump day both manual and electric and hopefully have my prop done.
Id love to mix up some black and white anti foul and give her a coat but I think Ill just go with the long life for now and in a few month pull her out before spring and put it on and if I feel like it a stripe on the hull
Select to expand quotesouthace said..HG02 said..cisco said..Trek said..
Cleaning purposes.... whats that Ramona, that's a use I haven't heard of?
Diesel fuel is quite useful for cleaning engine parts.
Early submariners bathed with it before going on shore leave due to the impossibility of having enough fresh water on a submarine for bathing purposes.
Even lubrication and in a tight spot as a rust and penetrating oil
Mu old Bukh had the secondary filter much the same as Bush Dogs the Bukh had been serviced regularly I was told maybe the
Cav filter was but the Bukh filter bolted to the engine looked to be 37 years old .
Probably because in my old boat you have to lay on the stern bunk and work between the cockpit floor and the stern bunk which would be less than 300mm makes it hard for the best of us and much worst when your on the autumn of life.
I removed one of the stern bunks now I have all the room I need laying on the bare hull and can lay in there for hours on a cushion. I cant for the life of me think that Id have more than couple of people sleeping on the boat at one time.
I'm moving the manual bilge pump some time soon as that sort of in my way when working side on the motor
My priorities are good rigging good sails good reliable motor and good anchor plus some instruments along the way.
ill finish the anchor system in the coming months and basic interior and keep working on her
You should carpet your engine room H20 it would be nice to lay on while tinkering with your Bukh or perhaps reading a book!
for christ sake don't give him any more ideas
how cheap is diesel compared to replacing the fuel pump and injectors,diesel will last a long time how ever the additives and moisture will not
Select to expand quoteRamona said..claverton said..
I'll be starting my diesel after more than a couple of years of it being idle. My question is should I empty my fuel tank and put fresh stuff in or is old diesel ok to use after it's a been sitting in the fuel tank for a few years?
It's only 40 litres in your case and I would suck it out and give away or keep for cleaning purposes etc. Suck it out from the bottom with an electric sump pump.
And Ramona knows of what he speaks, having had to give me a tow when I copped a pair of dead injectors due to old fuel.
And while on the subject, if you keep a jerry can of diesel for emergency purposes (a good practice), don't forget to use it and replace it regularly too.
