Need to clean / remove water from Kingfish tank

You said you pumped the tank out and it is now empty. Why do anything else? Sounds like you have it ready to go, as is?

How does the inside of the tank look? I replaced my fuel tank a few years ago as the top had corroded through when I cut the told tank up to dispose of it the inside looked shinny new. I was really surprised that it looked so good in there. I never had a old fuel issue though. IIRC I barrowed an air driven pump to empty the tank through the aft inspection port and when finished there was just a VERY small amount of fuel left in the tank and I soaked that up with a rag. How much old fuel is still in there? If there is not crud inside are you good to go? If not clean and I am just guessing but would 10 to 20 gallons of gas and the fuel tank cleaner perhaps work? Take a few laps with the boat on the trailer then pump that out put some new gas in and run it. On the other hand if your fuel source is selling you gas with ethanol and your tank looks clean inside the ethanol should accomplish a similar result over a tank or two - maybe fill it half full and run it out see how it goes. You said that it is running fine now that you have filtered out the existing crud so maybe all is well? Good luck.

Sounds like a plan.

Better safe than sorry when it comes to this stuff. The sending unit it very easy to pull - if I wanted to take it that "one little step further, just to be sure"... I'd use a hose with a small weight attached to it - stick that down the sending unit hole and shove it towards the back end of the tank. The weight will make sure it doesn't "curl up" and stays flatter to the bottom of the tank.

Andover_CT said:

Fuel looked clean, I filtered it again and ran thru my old Pickup.

Click to expand...

If you suspected the fuel was a problem for your boat why would you put it in your truck?
The fuel sock in the pump, in line filter, injectors can clog and damage can be caused.
45 Gallons of fuel cost what, $100? Buy or borrow fuel jugs and take it to your local recycling/hazardous waste center. In NJ it's free but even if you have to pay to get rid of it, it's worth avoiding the hassle of disabling your truck and the repair bill that will follow.
Don't roll those dice!

One last tip, if you buy a couple gas jugs get the ones like sold by VP racing.
Unlike the eco-friendly jugs with the restrictive green valves nozzle they are old school having a wide mouth with no restriction when pouring into your tank. It's easy to use and doesnt requiring fiddling to work or taking 20 minutes to drain. The eco friendly jugs are a PITA to use.
I have a couple of the VP jugs (5gals+ each) which I fill at the pump an use to fill my boat. Fast to fill and drain.

Andover_CT said:

$5 per gallon hazmat fee to dispose of. As I pumped out I sampled every 3-5 gallons approximately a quart. I had also rigged up a SECOND fuel water seperator so fuel was pulled out of tank, run thru boat mounted water fuel seperator filter, then thru the second fuel water seperator filter.

Did catch some water and algae in the first filter. Then poured into truck using fuel / water seperating funnel.

Fuel was clean and a nice clear fresh gas looking yellow.

Truck is 2005 Silverado with 225,000 miles... I have already put half thru truck and no issues.

Boat was running fine for 45 minutes to an hour before filter would plug / cause engine to loose rpms and go slower and slower.

Ran approximately 5 filters / 50 gallons this way and decided to pump out rest, clean tank and add fresh. I probably addressed most of water / algae issue by running boat and this was overkill.

I know my way around fuels and engines etc... truck will be fine. I was posting this looking for opinions on which fuel additive or tank cleaner would be best to use.

Thanks Tony

Click to expand...

I am curious. When you were running and the engine slowed down, did the primer bulb collapse or go soft? If the filter clogged, the bulb should collapse. If it didn't the slowdown may be something else. Even if it did collapse, you could have a vent blockage, bad fuel line, anti-siphon etc. I haven't seen gas grow algae, just diesel so I am not sure what you saw. I guess a water layer could have growth in it.
As to cleaning the tank, the best bang for the buck is to just add some fresh fuel, say 15 gallons or so and see how things go, If the tank walls are coated with shellac and you add ethanol gas, the gunk will dissolve and clog your filter. If all goes well, add more gas next time. If you are not using ethanol gas, the shellac if present will remain UNLESS you add something like DryGas or a similar product that has alcohol in it.