Draining dead gas on 1989 Sylvan 18' bowrider

[gregguy64]

HI, bought a 1989 18' sylvan with about 12-15 gallons of dead gas in her. Pulled off the fuel hose that goes to the cartridge water separator from the bottom end of the tank, and attached a 3/8 line going through the bilge drain hole to a 5 gal. gas can. Top of the tank has the fuel filler fat line, and a 2nd smaller tube, I Believe is the vent line. If I pinch the vent line with some vice grips, and blow some positive pressure in through the filler line with a 4hp shopvac on blower, will the dead gas start to flow. Is my setup safe enough? Its outside, shop vac has a 6' hose. are there better ways to drain that dead gas? Thx. guys, any advice is much appreciated. Cheers.

 

[Scott Danforth]

Pull the sender, pick up an outboard hose and bulb.....empty tank.

Then you can inspect and clean as requred thru sender hole.

Most likely your going to have to clean the tank

 

[Xj5]

I just had to do this with my flats boat. I had a little help from a mechanic. If you boat is on a trailer put the trailer jack tire up on a block and get the front of boat as high as possible. I let mine sit overnight and all of the water sinks to the back of the tank were it will be easy to pull out using the normal fuel line of the motor. I used a cheappump from walmart and it was pretty easy to suck out the water from the fuel line. I hope this helps

 

[tpenfield]

Set-up does not sound safe . . .

If you have an extra length of hose already attached to the fuel line, and that length of hose is extended out through the transom drain hole, you can use a fuel/oil hand pump and pump the gas out into the 5 gallon jugs with relative ease.

As Scott indicated, you may want to also remove the sender to get a look inside the tank to see if there is sediment remaining.

 

[fhhuber]

Set up adequate containers for all the gas before you start siphoning. And its much better to have an extra empty gas can than to be short one.

 

[QBhoy]

May take a while, but pull sender unit hatch off and suck it out using either a thin 12v submersible pump or an oil change suction unit. Safest way to do it...
Quickest way is to use the primer bulb (if you have one) or syphon into bilge and out the bung.

 

[Silvertip]

You can't siphon fuel from a tank that has an anti-siphon valve unless that valve is removed and replaced with a standard hose barb fitting. It is also not a good idea to use a big shop vac. All that air going into the tank cannot force fuel fast enough so there will be some blow-back of fumes. Your shop vac very likely does not have a fully enclosed motor so brushes arcing could touch off those excess fumes. Use a pump or siphon it through the standard fuel line.

 

[QBhoy]

Didn't know it had an anti syphon valve before on the lock up hose ? If it has, just remove the hose before the valve. Or more to the point I was meaning, stick a hose in the tank and run into bilge or out the bung.

 

[Dave-R]

Silvertip is right. every boat has an anti siphon on the fuel outlet to prevent a hose break filling the bilge with gas. I have a small 12 volt fuel pump that I either put the suction hose down the tank fill hose, or pull the fuel sender which is the best way. Then you can use a coat hanger and a white cotton sock to clean the tank using the fuel sender opening. I have used the pump also on the fuel tank outlet to the engine, but this is harder to prime the pump. Dave-R