Contaminated Fuel Help!!!

I have a 1981 20 ft Wellcraft V20 that I am told the fuel tanks are contaminated.

I just bought the boat and the tanks were already like that. They are approx 20g

aluminum tanks built into the sides of the hull. The tanks were working ok until

just before the last time he used them. The previous owner ended up having to

rebuild the carb and then did not use them again for some time.

Is there anyway I can salvage these tanks. I do not think they have been used in

while. I am wondering if the below would work:

1) Change Fuel lines.
2) Put a few gallons of high octane gas with a whole bottle per tank of some sort

of carb cleaner into each tank.
3) Shake trailer around.
4) Let sit over night and then drain.
5) Run some more gas thru tanks till clear
6) Change Fuel / Water Seperator filter
7) Install a in-line fuel filter of some sort for each tank.

What do you think? Is there a better way? Is this to much or not enough work? Any

help would be apprecaited.

I am not sure how they are contaminated. I have the work order from the boat yard

that re built the carb, It just states "Purge fuel pump and fuel line of

contaminated fuel. Do not connect fuel line to onboard fuel tank or carb warranty

is void. tank is contaminated and must be replaced."

I would love to replace the tanks, but I am working on a budget here. From the

research I have done, just the cost of the tanks alone is going to be $300. This

is not including any other parts needed to install them. Need to find a way to

repair and replace, if possible.

Thank you in advance.

[macojoe]

Well I have a 75 wellcraft and I just did this last year.

It is not that hard to get the tanks out.
You have to remove the tank covers and remove all clamps to the filler hose (Going to have to cut and replace these hoses) and remove hose. same goes for the vent hose and supply hose.

Then if they are still attached there will be some fingers tabs at the bottom of the tanks screwed into the floor. They will have to be removed also.

Slide tanks out!! Now you will have to drain the tanks out and find someone who will take the old gas??

After all gas is gone I cleaned well with a degreaser and water. Afetr that rinse well!!!!!!!!! Let sit in the sun for a day or two for the water to dry up.

Reinstall with all new hoses!! and clamps!! You don't want to reinstall with old hoses that may be less then perfect and have a problem!!

Even that I said it is a easy job it would be a pain to do it twice!

After your done you will have a hole new system!

Let me no if you need any more info!!

Good Luck

[bigshrimpin]

Call your local town/city recycling center, they will usually dispose of "bad" fuel free of charge.

Drain the tanks . . . just like MJ said . . . they're probably fine.

[macojoe]

There is nothing wrong with them tanks!! Its the fuel they are talking about.

We took out the tanks tonite. They were totally dry inside, not a drop of fuel. Visual inspection of the tanks looked good. Filled each tank with a full bonus size of engine degreaser. I added a bit of water to help slosh it around. Clogged holes with rags and shook the heck out of the tanks for about 5 minutes each. We are going to let the tanks sit overnight with the degreaser in the bottom before draining and flushing them tomorrow. We are going to replace all fuel lines including vent hoses. Going to to change fuel/water seperator and add an inline gas filter before the fuel water/seperator.

Since the boat has been sitting so long, we also took out each plug and poured some Marvel Mystery Oil into each cylinder.

Next job is electrical......great. There are as many bad wires as wires that don't go anywhere on this boat. I put in a new ingnition switch tonite, but still no power to the trim, blower, nav lights, or bilge pump. Matter of fact the only thing electrical that works are some bright interior lights. They do run thru the ignition switch, but work regardless of whether or not the switch is on. Another new quandry........er. lol ;D

[axespino]

On my 73 V20 the gas in tank had turned to varnish. I drained the tanks and then washed them out at the car was with the power hose. There was plenty of gunk coming out. Had problems later on with small pin holes in dip tubes so I had to steam the tanks and have a welder weld some fittings on the back of the tank about one inch from the bottom.

Thanks for all the help.

We took both 20 gallon gas tanks out. Filled them each with a full can of engine degreaser. Sloshed them around and let them sit on and off for 2 days. Rinse them throughly with tons of water. Let them dry 1 day and then put 1 bottle of isoproyl in each tank. Let stand another few days draining. Replaced all fuel lines and the gas/water fuel filter.

When draining the tanks, no sludge or gunk of any kind came out. Water draining from the inside looked almost drinkable. Inspection of the inside of the tanks with a small flashlight showed nothing but clean, shiney insides.

Tanks are now back in and ready to go.