how old is too old for gas

Hey Guys,

I have a 1977 33 ft CC coho with 2 100 gallon fuel tanks. There is approx 25 gallons in each tank. However the gas has been in there for approx 2 years with no Stabil treatment according to previous owner. I wanted to pump it out and start fresh but I have no idea where to get rid of 50 gallons of old gasoline in (brooklyn NY) boat yard wont help me. If I just added 75 gallons of fresh gas to each tank would that cause problems or would it mix with the old gas and burn ok? What is the time limit before gas becomes unuseable or dangerous to the system. Can you mix old gas with new? I have completely repowered both engines with new Chevy 350's inboards, new carbs, distributors, manifolds etc. but havnt started the engines yet. Any help would be appreciated. I cant start my season until this problem is addressed.

Thanks,
EP

If the Gas that was in there has any percentage of Ethanol in it, I would be draining it all and flushing everything out. Hoses, Pumps, Carby, tanks etc.

As far as getting rid of old Gas, I know what I would do with it, but then, we don't have such tight restrictions here. Can't you just pump it out and take the containers to a recycling depot?

I pumped out 7 year old Gas from my boat. It pumped out okay, but when draining the tank, it was like pouring out black treacle, and it set solid in the lines as well as the crud in the tank and filters, pump and carby.

Bruce.

My boat missed a season and I ended up with year and a half old fuel. It didn't smell right so I pumped it out into 5 gallon cans. Every time I filled my truck up I added some to the tank. About 2 1/2 gallons in a 20 gallon fillup worked OK. Took a while but the only other option was calling Safety-Kleen and having them dispose of it as Haz-Mat.

I've used old marine fuel in my cars and trucks, but never more than a couple of gallons/tank fill. There is a product that you can buy that is supposed to remix phase separated ethanol laced gas, however, when you read the directions (you need to mix well, a real trick when boat is on the hard) and look at the cost, recycling it in a car of truck is a better way, IMHO. My engine has an electric fuel pump, so I just disconnect the fuel line at the carb, hot wire the oil pressure switch and use a short length of fuel rated hose to transfer fuel into 5 gal gas jugs.

Thanks for the replies. There is no where to deposit gas in bklyn rather than hiring a haz mat team to dispose of it.$$$$$$ I took a shot & tried to fire the engine with it as is and the engine roared to life and commenced to idle. I think it may be ok. I am going to buy a box of clear inline fuel filters in addition to the fuel/water seperators I have and watch what is flowing through it and make my decision if I am to leave it in there. If I see blackish/flakey fuel I'll halt. If I see golden liquid and the old gas in there continues to burn I'm gonna run it through. I'll let you guys know how it turns out.