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Fuel tank full or empty?

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mharvey

Member
What is the consensus on winterizing with a full tank, or bone dry? I know to use a stabilizer but was not crazy on leaving 30+ gallons of gasoline for use 4-5 months later.

I was thinking of loading the carb with a good mix of stabil and drying out the fglass tank. Would just 2-3 gallons in the tank be a good idea, then pump it out next season, so you do not let the pump and lines dry out?

Thanks for any input.
 
Fill tank. Shut off fuel tap. Run engine until it dies out. Should be good for at least 6 months that way.
If nothing else, you'll be happy in the spring that you bought gas way back when it was under $4!
 
the outboard it all gets drained dry, the inboard it gets topped off, double dose of marine sta-bil and a bottle of startron, engine is MPI so a mix of stabil, gas and 2 cycle oil gets run theu motor .
 
I usually leave the tank level at wherever it is, add Stabil, then top it off with fresh gas in the spring before first startup.
Never had a problem.

Rod
 
I never ran my 4.3L carb dry w/Stabil in the fuel. I didn't want any residual fuel to dry out in the carb bowl and leave varnish dust behind only to plug up the idle circuits in the spring. I also don't wait for winter to add Stabil to the gas--it begins to degrade after 30 days. Read the label--a double dose of Stabil will keep the fuel fresh for 12 months. If you use SeaFoam in the fuel tank it has stabilizer in it and it will also clean out any varnish or gum from the fuel system while the boat sits over winter storage.

When I would change the fuel/water separator filter in the fall for winter storage I would fill the new filter w/8 ounces of SeaFoam before installing it. I then ran the engine for two minutes or less until the exhaust was smoking. That would fill the carb and coat the intake manifold, valves and pistons w/SeaFoam to soak and clean/protect over the storage period. The engine would turn over right away in the spring and smoke for a few minutes while the SeaFoam did its job of cleaning out any carbon buildup in the engine.

You never know if the boat will have to sit for a period of time other than winter. I wasn't able to get on the lake until May 25th (sat from Oct) last spring due to the heavy spring rain we had here. The reservior was 19' above summer pool and all but two ramps were submerged/closed. The two open ramps required you to back your boat down a steep hill about 100 yards one car at a time. There were no docks--you had to tie off to a tree.
 
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That sounds good also, I have used Seafoam before for cleaning, but is there more than one product in the Seafoam family. Which one of the Seafoam products do you prefer for the winterization process? I do not know what all Lucas fuel additive does, but I do run it some during the season. It seems to work out bad fuel or maybe pick up small amounts of water in the fuel, or just clean the system somewhat. Anyway, if it starts acting up I add some Lucas and it seems to help.
 
No experience, have never used the octane booster. I really thought/think most additives are money out the exhaust, but I am sure with enough trial and error, some are worthwhile.
 
I learned the hard way in 1999 by using octane boosters for my 1994 chevy 350 v-8. After two tank fill-ups w/octane booster my plugs were completely smothered. Truck nearly stopped. They looked like Brown lollipops. The engine had a knock that caused it
to shake violently and knock loudly. We used a GM product to clean the carbon from the piston tops and valves. Poured half of a pint in it thru the throttle body w/engine running and flooded it w/the other half can. We let it sit overnight then ran the crap out of it for 20 minutes on the road to blow out the carbon. It worked perfectly.
 
This year we had a problem with fuel boat would diesel found out the fuel dock we were buying gas from had water in their tanks. One tank of Valvtect fuel from a different fuel dock solved all our problems, if you can find this fuel near you there is no need for any extra additives. In my opinion it depends on where you store you boat on whether the tank should be full if you have freezing and thawing conditions I would fill the tank less room for condensation. I store mine indoors temp never drops below 50 degrees plus we take it out a couple times a month during the winter. Here's a link to Valvtect
http://www.valvtect.com/marineFuelGasoline.asp
 
"I usually leave the tank level at wherever it is, add Stabil, then top it off with fresh gas in the spring before first startup.
Never had a problem." (Rod)
Thats exactly what I do as well.

I also run the engine for about 10 mins to warm up the oil to change. This gives a chance for the Stabil to make it into the carb.

Wrench
 
Maybe for a carbed engine it would be wise to disconnect the fuel pump on the final run after oil change etc, and let the carb run out of gas? Then there would be no gas residue to dry up and leave a residue next spring.
Just a thought.

Rod
 
Guys, can't give the difinitive answer but here is my rcent expeerience living in the South. My Merc 260 I/O was put to sleep because of an engine problem. I drained the tank dry. Pulled the tank level sender and sucked the tank dry,every drop. A few months later I got back into the engine problem and added 15 gallons of fresh fuel and the recommended amount of Stabil. The engine problem was not fixed so Seafoam was added and it sat another 9 months. Finally getting a Merc service bull. I resolved the problem and started the engine on a 1 gallon can of fresh fuel. Ran perfect so I switched over to the boat tank. Bad decision. Fuel went BAD. Inside of carb was eaten up, plugs fouled, valves stuck. Stabil and seafoam are short term solutions. Six weeks at best. The tank was pulled and gummy substance cleaned out. The walls were coated with slippery stuff, maybe from Seaform ? I do use Seafoam in my motorcycle because the Ethanol was rusting the inside of the tank and it has stopped the rust.
Running out the gas in carb lets it dry out and residues form.
Keeping fuel in evaporates the volatiles and leaves varnish behind.
Honestly don't have the answer in the South, maybe it's different in the North.
 
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