Bad fuel, real bad, and real old..ideas ?

[Fishhook2120]

Background: My boat sat for 3 years with fuel in the tank. I pumped all the fuel out I could with the primer bulb and let it sit for a few months before I got to working on it. The tank is aluminum, and has no access except the elbows welded on for the 3 hoses. I got the engine running using a gas can, after rebuilding the carbs. (DT90) I filled the tank and added a bottle of Seafoam to it and hit the water. I was able to run at half to full throttle, but no start or idle.

I have the main carbs on the bench now, and have rebuilt the "starter" carb already. I am going to clean/rebuild the fuel pump tonight, and reassemble everything.

I will test and run on a seperate tank for now, but need to deal with my in-hull tank. When I pulled the filter after running, I found redish tent, and lots of tiny particles that would settle to the bottom of a glass jar. After seeing that, I decided to redo the carbs again, which is where I'm at now.

I have read about using E85 or E100, but will that disolve the particles ? I feel I need to drain the tank again, but how will I get the tank "clean" without access to it ? Any suggestions would be great.

Thanks

Fishhoook2120

 

[robert graham]

Re: Bad fuel, real bad, and real old..ideas ?

That's the big problem with built-in tanks and I understand the coast guard doesn't allow any drain lines from tanks to bilge or outside for safety and environmental factors. If you could somehow circulate(by pump) that contaminated fuel through a filter, enough to remove all that particulate matter, then pump out all the old fuel as much as possible, then refill with fresh gas, then you'd be in a lot better shape. You still need a fuel/water seperator in the feed line to remove whatever trash may be in there. Many folks have to cut into the deck to remove/clean/replace contaminated fuel tanks. Good luck!

 

[Fishhook2120]

Re: Bad fuel, real bad, and real old..ideas ?

Thanks, I am working on a pump system now. Think I will pump out what is in there now, then repeat the process one more time before pulling it thru a filter. Seems to be a ton of stuff in there now.

Think Seafoam is as good as anything to break this varnish/gunk down ?


Fishhook2120

 

[robert graham]

Re: Bad fuel, real bad, and real old..ideas ?

I think the recirculation method will really be using that contaminated fuel to help remove most of the particulate matter. You might also use an air hose to agitate the fuel to keep the suspended particles in suspension and prevent them from settling in the bottom of the tank. There is a product at Autozone called Berryman's B-12 that you can buy in a gallon can, and it is some good strong solvent. The recirculation pump and filter system is something that you will have to work out so as not to create any fire hazard and a fire extinguisher handy and working outdoors with good ventilation will be important. How much total contaminated fuel is in your tank? This can be done with some thought and planning. Good luck and let us know how you do.

 

[99yam40]

Re: Bad fuel, real bad, and real old..ideas ?

I think the recirculation method will really be using that contaminated fuel to help remove most of the particulate matter. You might also use an air hose to agitate the fuel to keep the suspended particles in suspension and prevent them from settling in the bottom of the tank. There is a product at Autozone called Berryman's B-12 that you can buy in a gallon can, and it is some good strong solvent. The recirculation pump and filter system is something that you will have to work out so as not to create any fire hazard and a fire extinguisher handy and working outdoors with good ventilation will be important. How much total contaminated fuel is in your tank? This can be done with some thought and planning. Good luck and let us know how you do.

Placing an air hose in the tank to agitate sounds like a very bad idea, there will be way too many explosive fumes being generated. And air or anything else moving through hoses/lines will form static electricity if not grounded properly
I am sure there are places that will clean the fuel tanks properly, but may be expensive.

 

[Fishhook2120]

Re: Bad fuel, real bad, and real old..ideas ?

I had pumped all the fuel out I could from the primer bulb. There is between 10-15 gallons of fresh gas in the tank now, that is mixed with the gas left after pumping the first time.

I was planning to pump the fuel out that is in it now direct out of the boat via a hose. Then put 8-10 gallons of fuel and a solvent back in it, then ride around on the tralier for a couple days. Then pump it out again, then start a filter process. Does this sound like a decent way to do it ?

thanks

Fishhook2120

 

[robert graham]

Re: Bad fuel, real bad, and real old..ideas ?

That seems like a reasonable good plan, but whatever it takes to get rid of all that contaminated fuel before it just gets sucked right back into your carb jets. Maybe install a Walmart($27)fuel/water seperator on your transom, then you can run your motor a while on mostly fresh fuel, unscrew the fiter cartridge and dump out the debris, screw it back on and run motor some more, keep dumping, etc., until your fuel system is clean. @#$%built-in fuel tanks! My brother-in-law got fuel contamination(water) in his 60 gallon built-in tank on his KEY West boat, finally had to remove T-top, console, cut deck, remove/replace the tank. a real PIA! His new 40 gallon aluminum tank has a Stainless drain pipe with Stainless valve and Stainless pipe cap, drains to bilge, not coast guard approved, but will help next time fuel contaminated. Good luck and you'll get it done!

 

[Fishhook2120]

Re: Bad fuel, real bad, and real old..ideas ?

Thanks, I will get started on it this weekend. One thing for certain, I won't be running any gas through the engine from the tank untill it's clear as drinking water. I have cleaned/rebuilt the carbs twice now, and the fuel pump and the starter carb. Not a fun job for me at all. They are as good as new or better right now.

Yes, the no-access built-in tank is crazy not to have a drain. I have a 8" access cover and that's it, and even worse, there is only 3, 90 degree elbows under it to do anything to the tank. My boat is old and not made anymore, it was a small boat builder in eastern NC that hasn't built a boat in a loong time. If I have to get the tank out, I might as well sink it as a reef.

Oh, and this baot hasn't run E gas at all, ever.


Fishhook2120

 

[robert graham]

Re: Bad fuel, real bad, and real old..ideas ?

I'm confident that you can clean out that tank and be in great shape. The Stabil Marine Fuel Stabilizer all the time and the fuel/water separator are a couple of items that you're going to need, for sure. Good luck and don't blow yourself up messing around with that gasoline!

 

[nash1970]

Re: Bad fuel, real bad, and real old..ideas ?

I'm hooking up a auto electric fuel pump up so I can drain my tank into my truck when I'm done boating .

 

[Fishhook2120]

Re: Bad fuel, real bad, and real old..ideas ?

I have a spin on 10 micron filter on the boat now. Once I get the tank drained once, I will run through the filter and thinking of adding a inline see through filter while I clean the fuel. I plan to replace all hose to and from the tank also. My boat is a 91, so I figure it is due.

Fishhook