3 year old gas

Howdy. Just traded in the old 20' bowrider for a 23' chris craft scorpion. pretty cool boat. brand new jasper 350 crate motor, cammed, springs, lifters, high rise headers, thru hall, etc. anyway the boat was in storage for 3 years with half a tank of gas in it (70 gallon tank). It runs really good and strong, starts right up, but has a miss below 2000 rpms and is idling a little rough, which i'm attributing to the old gas. I was wondering if anyone knows of any good additive or anything i could add to the gas? if not do you think it would be better to run this gas out of it before refilling with fresh or just fill the tank with fresh now to dilute the shittyness of the old gas? I was just thinking the TW motorheads out there might think of something I hadn't. thanks everyone.

 

Gas that has not been treated is usually crap within 6 months or less. I would try to get that stuff out of your boat and put fresh gas in. Sta-bil only works at keeping good gas fresh, it will not freshen old gas.

edit. Sorry, Chris beat me to it.

 

Fuel begins to turn to laquer after about 3 months unless something like sta-bal was added. I would drain the old gas and start with new

 

Pump that crap out! Good gravy.

 

damn. thats like $100 worth of gas. where would i even dump it? besides the chesapeake or my storm drain!

 

^^^ looks like it's been covered pretty well, but just another suggestion...after you get the old gas pumped/drained out, running a tank of premium through it with some injector cleaner couldn't hurt....this is asumeing it doesn't already require premium.

 

i would add a bottle of HEAT water remover and pump about 5 gal of new gas into it. the new gas will clean up any sludge type crap that some of the old gas has created. done this many times with generators for fuel systems and has never failed

 

alright so i'm going to pump the rest of the gas out tomorrow. Can any of you gurus think of anything else I could do besides just get as much out as possible, adding a full tank of fresh gas, and changing the water seperator/ fuel filter? additives? tricks? carb cleaner? or should the new gas clear everything out? thanks guys.

 

If the boat sat for three years without being ran, it would be a good idea to pull the float bowls off the carb and clean everything out. Check the needle and seat while you're at it and give it good cleaning. Old gas can really gum up the inside of a carb if it sits there too long. Should be pretty easy and quick too.