Suggested procedure for purging fuel system?

[hanleyclifford]

Thanks for all the help! Got it running yesterday and went for a spin before sunset.

That's frustrating about the Racor filter, as my mechanic installed that one after telling me what I had before was not USCG approved!

One thing I noticed while pumping bad gas out of the tank yesterday was a lot of black sediment in the gas. Wondering if this sediment is normal, perhaps from old gas, or if it means my gas tank is rusting (which would be huge pain in the neck, because I'd pretty much have to remove the engine to get the existing tank out)

Another day, another project..
NS

Make sure all your fuel system hoses are ethanol tolerant. The black granular sediment could be hose fragments. That includes the filler hose which could be a PIA to replace.

[Al Schober]

I had to replace my fill hose - the old one crumbled in my hand! Getting the old one out was easy. Installing the new one required removing the fill fitting as I couldn't spring the new hose into place.
As for the tank, see if a magnet sticks to it. If it does, put the tank on your list for replacement.

[JOHN COOKSON]

The vent for my fuel tank (a copper tube coming through the deck) snapped off and a lot of water got into the fuel tank. NatySailor (Tartan 27/ 1963 Atomic 4 near Baltimore, MD)

If the copper vent is attached to the tank electrically somehow this is not a good arrangement. Copper will yank electrons out of almost any metal, especially steel and aluminum.

+1 on the black stuff comming from the fill hose.

TRUE GRIT

[NatySailor]

Why metal bowl for Racor filter?

Wondering why a metal bowl is needed for the Racor filter. My guess is that it is a safety hazard in case there is a fire below and the plastic melts. But there's a ton of rubber hose in the same area that could easily melt as well.

I asked the mechanic who installed the filter and he said he installed the clear plastic for me so I could easily see if I had any water in the fuel.

So my question is, does this really make that much of a difference?

[Al Schober]

Two folks who might find issue with the plastic bowl. One is the Coast Guard if you happen to get boarded - that plastic bowl stands out like a sore thumb. The other folks are those who underwrite your insurance (only an issue if you need the insurance...).

[dvd]

naty

Another thing you may need to consider is yanking out that 40 year old science experiment of a tank and installing a new Moeller plastic tank. My original tank was made of sheet metal and after getting it out it was confirm d that I never would have been able to get all the gunk out of it. Now I have a new semitransparent tank with a fuel gauge that insures a clean fuel supply.

For what it's worth. Also plastic tends to have less condensation issues.

Dvd

[hanleyclifford]

Interesting how the USCG is good with a plastic tank but not a plastic filter.

[HOTFLASH]

USCG and plastic and gasoline

I do believe the bowl in the fuel filter is a hard rigid plastic which can break when hit or over-tightened onto the metal separator, and the gas fuel tank is made of a more flexible plastic and is without any screw-in port. The differing plastics have differing properties. My guess is that the differing regs have something to do with that.

[Dave Neptune]

The clear plastic will breaks down and gets brittle after some time, this makes them prone to cracking. They usually start to get a tannish color when the plastic is breaking down. The poly fuel tanks do not break down with exposure to gas and they will break down in the sun.

I am on my third Racor plastic diesel type as I want to be able to "look" and see if there is anything like water or sand getting past the "tank". I had one crack and not leak. I found it because the crack would allow an air encroachment which reduced fuel pressure (permanent gage mounted) and performance off idle. The fuel pump could just keep her idling and little else. Since then they seem to last about 6~8 years before they turn color. Note I have never changed a filter on any of the 3 Racor units yet a sure sign of a clean tank~so far.

Dave Neptune

[CalebD]

One thing I noticed while pumping bad gas out of the tank yesterday was a lot of black sediment in the gas. Wondering if this sediment is normal, perhaps from old gas, or if it means my gas tank is rusting (which would be huge pain in the neck, because I'd pretty much have to remove the engine to get the existing tank out)

Another day, another project..
NS

Naty,
If your T27 is like mine it was built with a Monel fuel tank. Mine has now lasted for some 48 years without failure. I would not be in a big hurry to replace it.
Regarding the black sediment you found, I found the same thing when I pumped out the bottom of my tank. That black sediment, heretofore known as crud, is mostly water that some bacteria or algae has grown in. The water comes from E10 fuel that has sat around and the ethanol has separated from the E10 mixture. The alcohol absorbs moisture from the air, hence water, and lots of organisms can live in water.