bad gas-molded in tanks

[hotpops]

I have a 67' stevens with molded-in tanks with old gas in them. Imean OLD!!!!!!! I have an electric fuel pump and want to recirculate gas from output of pump into fuel fill to break down contamination and eventually pump all the bad gas out. Is there an additive I can add to this process to help breakdown the residue and allow me to end up with good fuel to run the motor on? The motor is a 1971 125 johnson running on 50/1 mix. Summer is here and I want to go play. thanks for any help you can give.

 

[roscoe]

Re: bad gas-molded in tanks

Definitely have to get the old gas out. I don't think you can hurt anything by adding some fuel conditioner to the old gas, but don't know if it will help either. I would pump out as much as possible. Then add a few gallons of fresh and recirculate as you described. Then pump this out and wipe out the tank if possible. Replace the pickup tube sock, and fill with fresh.<br /><br />Be safe, don't need any extra fireworks this weekend.

 

[hotpops]

Re: bad gas-molded in tanks

thanks Roscoe, I figured flowing gas would help get things cleared out, but didn't know if there was any solvent that would speed up the process. The tanks have built-in baffles but figure there are passages in the bottom to allow the fuel to flow back to the pick-up.will give it a go and see just how clean I can get it. not able to get inside the tanks at all.

 

[roscoe]

Re: bad gas-molded in tanks

You should have an access hole somewhere, so you can access the sending unit for the guage. If you remove the sending unit, you might be able to reach inside or look inside to inspect. If its just a little gas letf in there when you are done, I wouldn't worry about it. But if there is a layer of varnich, crud, or sediment, you want to get it out.

 

[Solittle]

Re: bad gas-molded in tanks

If the gas is as old as you describe, your best bet would be do drain the tank and dispose of the gas. It will gum up fuel filters and carbs.<br /><br />I had a boat some years ago and had to have someone drain the tank (big $$). The crap that came out was the color of dark orange juice and smelled worse than terpentine. You don't want to put that stuff in your motor.

 

[hotpops]

Re: bad gas-molded in tanks

my thanks to roscoe and solittle. unfortunately, the boat was a racing boat in it's former life and there never were any guages onboard. will try the recirculating flush this weekend and figure by August they will be cleared out enough to take a try on the lake. taking the paddles along for sure anyway.

 

[Fouled Plug]

Re: bad gas-molded in tanks

An inline fuel filter/seperator will be a must. Get a good quality unit, and some spare filters just in case. Crud will probably be coming out of those tanks for a while.

 

[suzuki40]

Re: bad gas-molded in tanks

I just went through the same problem with my 79' johnson seahorse. This is the only way I got the tank clean as a whistle.I filled the tank with 2 cans of carb spray cleaner,drain the old gas, just open up the tank and spray two cans of cleaner into it, shake it around and let it sit for about an hour. Then removed the fuel line. then take off the petcock, (fuel on and of valve)<br />removed the gas cap. Take it to the carwash and use the powerwasher on it. It is going to get you wet and dirty. but, Im telling you it blast all that crap out of there.Trust me, it cleans it like new. after cleaning, put a little rubbing alcohol in the tank and swish it around. open it up to the air and let it dry out. you are ready to go.<br /><br />Suzuki40

 

[moderator1]

Re: bad gas-molded in tanks

Moving to Boats.