how to clean a fuel tank

[Don O'Gorman]

I have a 1985 Sea Ray Seville Cuddy with a 26 gallon fuel tank. Apparently, dummy me forgot to put stabil in the tank last winter and I have crud gumming up the fine filter at the inlet to the carb if I run it for only a short while.... like 6 - 10 miles. I have done a lot of work this summer on the boat ( new impeller, new outdrive lift cylinders, new fuel pump, rebuilt the carb among other things) but now I need to know how to clean out this tank. The opening where the sending unit is is only maybe 4 inches wide so how do you clean the inside if that is the only access point? Also if I get it cleaned out should I put an additional inline filter in the fuel line between my tank and the fuel pump or is that not necessary? Any and all help is appreciated. Thanks

Don

 

[Lazy Daze]

Are you positive your tank is dirty... what about old fuel hoses? They deteriorate on the inside.

Don't beat yourself up - the lack of Stabil has absolutely nothing to do with causing/preventing crud. Totally separate things.

Siphon (safely with fuel rated siphon) all of the gas out and then you can better inspect the tank. You'll still have fumes - so be mindful of what you use when inspecting.

 

[Skybolt]

As mentioned I doubt not using Stabil caused any issues. It is more likely the ethanol gasoline. Especially in that year boat.

I would put in a Racor fuel filter as close to the engine as possible and replace the rubber fuel lines. That "Crud" you're referencing sounds like the typical ethanol "cleaning" of the fuel lines and it ends up where ever it is stopped. Rubber fuel lines from that era are not ethanol rated and will break down when used with ethanol.

Most of the ethanol complaint's you read about are because of this, and mostly on older boat's. Newer boat's don't typically have these issues.

 

[Don O'Gorman]

Ok sounds like good advice.... The only rubber fuel line I have is a short one that is about a foot and a half to 2 ft long from the gas tank to the fuel pump. After the fuel pump the line to the carburetor is steel or iron I'm not sure which. Should I put the filter in the line between the fuel tank and the fuel pump because I'm not sure how I would install one after the fuel pump given the steel or iron line that goes up to the carburetor.

 

[Skybolt]

Ok sounds like good advice.... The only rubber fuel line I have is a short one that is about a foot and a half to 2 ft long from the gas tank to the fuel pump. After the fuel pump the line to the carburetor is steel or iron I'm not sure which. Should I put the filter in the line between the fuel tank and the fuel pump because I'm not sure how I would install one after the fuel pump given the steel or iron line that goes up to the carburetor.

Yes, between tank and pump. And get E-10/15 compatible fuel hose.

 

[Don O'Gorman]

Sky...we are in the same part of the world...I am out of the Gunpowder....I fish around the narrows frequently. anyway my next question is: in addition to installing the inline fuel filter should I do something with the fuel tank or will the 3 filters ( inline, fuel pump, and carb inlet) take care of ridding myself of the gunk over time?

 

[Skybolt]

Sky...we are in the same part of the world...I am out of the Gunpowder....I fish around the narrows frequently. anyway my next question is: in addition to installing the inline fuel filter should I do something with the fuel tank or will the 3 filters ( inline, fuel pump, and carb inlet) take care of ridding myself of the gunk over time?

So many great people here at CSR in general, but a lot from the bay area for sure. I have met so many members from this area here I can't keep up with them.

If the fuel tank is dirty the Racor will clean that out over time if it is not horrific. If the tank is really bad the you may need to siphon all of the gas out and inspect as @Lazy Daze suggested. If not the Racor may need to be change a few times. I would get the Racor setup and after a full fuel tank runs out, change the filter. Then cut the changed filter in half and see what you have. Also the big benefit of the Racor system is the ability to drain the cup and see what's going.

When the tank is run down to 1/4 or less, you could put an inspection scope in there and see what you have also. No siphoning needed at that point. Just be carful with the fumes.

 

[Don O'Gorman]

Got it ...thanks so much