How do I clean my fuel tank?

TheBoyScout

Thanks doesn't buy gas...
Nov 13, 2014
306
207
San Diego
Name
Ray
Boat
Bayrunner Baja 23 "Rough Rider"
I just replaced all fuel lines and filters to my outboard because it was dirty and fuel pump went bad. I checked what the inside of the tank looked like through the fuel sending unit and i can see flaking varnish at the bottom of the tank. I siphoned out all of the fuel and now am looking for a way to clean out the tank. Ive done a lot of research and have come gotten a lot of ideas. The flakes seem to come off really easy when i scraped them, what have you guys used?
-I am trying to avoid introducing water and soap into the system
-Denatured alcohol looks like the best bet and wont hurt the fuel system if a small amount is left in (i cant find where to buy it though?)
-i see a lot of people using acetone, this option seems appealing
-also startron fuel tank cleaner

I was thinking about putting acetone in the tank then driving the boat around with lots of starts and stops then letting it sit, then parking it on an incline so I can siphon as much as I can out.

What do you guys think?
I already got a quote for Roys fuel polishing but I don't wanna spend $700. I want to try it DIY first and see if I can save a few bucks. The tank doesnt look too bad and the flakes come off easy so Id like to try a DIY option first.

Thanks!
 
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Apr 8, 2012
345
132
Cal.USA /loreto bcs./lopez mataos b.c.s.
Name
avery gilleland
Boat
tuna can
I had a similar problem! Gasoline is a great solvent when fresh, I filled our tank half full and drove around as you mentioned then drained the gas into a funnel with a screen filter and repeated the process a couple of times. I would also add a replaceable filter system. I ended up using the filtered gas in my truck so I didn't waste it or create a hazardous mess. I hope this helps .
 
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Da Mad Anglah

Old fut who still misses home on da islands
Oct 21, 2020
57
68
Idaho (and sometimes Honolulu)
Name
Chris
Boat
'93 18' Weldcraft "Rod Rage"
I agree, fresh fuel, drive around to slosh all that shit around, pump it back out, filter it, do it again if necessary.
I used my MityVac pump to suck up all the crap on the bottom of the tank, it went really fast (only a 30 gal tank on my boat though) and got all of the stuff out that I could see from the tiny fuel-sending unit's hole. Putting the boat's front on blocks to get everything to fall to the back where the opening was made it easier to get most of the crap out. What was left was easily caught by the fuel filter. Changed it out after a month (and no issues during that time) and tank now looks perfect.
Good luck!
Chris
 
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TheBoyScout

Thanks doesn't buy gas...
Nov 13, 2014
306
207
San Diego
Name
Ray
Boat
Bayrunner Baja 23 "Rough Rider"
Avery and damad I like your idea but I really don’t wanna run that fuel through the boat or my car really. I was thinking about putting in a couple gallons of E85 and letting it slosh around (I guess the higher ethanol content cleans varnish well) and then siphoning out and recycling it.

Does anyone one have any experience with acetone and fuel tanks?
 
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marlyn

I Post A Lot But I Can't Edit This
  • Dec 18, 2005
    8,806
    5,488
    So Cal
    Name
    mark
    Boat
    21' skiff and 12' portabote recycled from milk jugs
    Avery and damad I like your idea but I really don’t wanna run that fuel through the boat or my car really. I was thinking about putting in a couple gallons of E85 and letting it slosh around (I guess the higher ethanol content cleans varnish well) and then siphoning out and recycling it.

    Does anyone one have any experience with acetone and fuel tanks?
    Ohnestly gas is the best solution and just run it though a screened funnel(t shirt)right into your car like was previously mentioned.E85 is good for nothing and is probably contributing to the issues if not causing them,ethanol turns to varnish and fubars everything.Make sure to use a fuel stabilizer in the future as a preventative.
    Good luck!
     
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    plj46

    I Post A Lot But I Can't Edit This
    Jan 7, 2008
    8,801
    12,072
    Socal
    Name
    john
    Boat
    24 ft grady white
    Don't put acetone in the tank and then run the motor.Cleaning the tank with acetone would be ok but get it out of the tank before running the motor.
     
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    TheBoyScout

    Thanks doesn't buy gas...
    Nov 13, 2014
    306
    207
    San Diego
    Name
    Ray
    Boat
    Bayrunner Baja 23 "Rough Rider"
    Of course I’d clean the acetone out, put some fresh fuel in then siphon it out just to make sure most of the acetone is out
     
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    The Right Kind

    Slave to a Boat
  • Jul 9, 2003
    1,303
    1,131
    Santa Barbara
    1212
    Name
    Gary
    Boat
    The Right Kind - 31' Cabo Express
    I use one of these to clean out the black water tank on our MH

    Valterra A01-0184VP Master Blaster Tank Wand with Power Nozzle




    1614096984058.png

    Actually I made my own out of PVC. Hot water and Dawn detergent should work. Drain it and dry by stuffing a towel in there, get it out with a coat hanger then leave it open for a few days to completely dry. Fill and change filters often.
     
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