Winterizing-Fuel Tank, Empty or Full; Stabil or Not?

[Farmall.Dude]

I'm the original owner of a 1994 Fourwinns Horizon 180 with a Cobra OMC 5L V8. In the 19 years I've owned it, it has only twice been 'professionally' winterized. I've NEVER had a lick of trouble (that I didn't cause myself) with it. I have also Never run Ethanol in it, which is getting harder and harder to maintain! I have always (until recently) filled the tank at the end of the season. I have never used Sta-bil. I'm thinking I should start. I'm looking for your opinion on the topic. Should I fill the tank and add Sta-bil, Fill it without Sta-bil or leave it (near) empty? In any case, I will NOT put Ethanol in it.

Also, I have always removed all the hoses and opened the petcocks after running Marine Antifreeze through it. The last time I had it done professionally, they left the hoses on and closed the petcocks after running antifreeze through it. It was fine, of course. Do you leave hoses attached or remove them? Just curious...

 

[jeffnick]

Re: Winterizing-Fuel Tank, Empty or Full; Stabil or Not?

One More Time Around: Winter Gas Tanks - Full or Empty

If you leave the hoses off and the petcocks open, there's no question of the state of the motor.

 

[Another retired guy]

Re: Winterizing-Fuel Tank, Empty or Full; Stabil or Not?

If you've never had a problem with the gas, then why change your routine? There is no right or wrong answer re stabilizer/no stabilizer or ethanol/non-ethanol or tank full/empty . Everyone has their own opinion, and personal experiences vary depending on such things as location; length of storage; hours of use etc....whatever works for you is the way to go

 

[HT32BSX115]

Re: Winterizing-Fuel Tank, Empty or Full; Stabil or Not?

Yeah. I have always left my 44 gallon tank with about 10 gallons or so of fuel in it from SEPT to about JUN the next year when I fill it up with fresh fuel.

No Stabil or other snake oils.

I do store my boat INSIDE though. Not in the water or out in the weather.

Here's what a surveyor says. (at least about what happens inside a tank)
It's not just his opinion........And he backs it up with some verifiable facts.

The Myth of Condensation in Fuel Tanks by David Pascoe: Boat Maintenance, Repairs and Troubleshooting

ymmv,


Rick

 

[tpenfield]

Re: Winterizing-Fuel Tank, Empty or Full; Stabil or Not?

I go empty tank . . . By siphoning the remaining fuel out. Some of it I use for making the EFI 'cocktail' to fog the engines. The rest goes into the cars.

as far as cooling, I run the antifreeze and drain things . . . That way I do not have to disconnect intake hoses, etc.

 

[tpenfield]

Re: Winterizing-Fuel Tank, Empty or Full; Stabil or Not?

Yeah. I have always left my 44 gallon tank with about 10 gallons or so of fuel in it from SEPT to about JUN the next year when I fill it up with fresh fuel.

No Stabil or other snake oils.

I do store my boat INSIDE though. Not in the water or out in the weather.

Here's what a surveyor says. (at least about what happens inside a tank)
It's not just his opinion........And he backs it up with some verifiable facts.

The Myth of Condensation in Fuel Tanks by David Pascoe: Boat Maintenance, Repairs and Troubleshooting

ymmv,


Rick

another thing about Dave Pascoe's article, is that the fuel tank will have a substantial amount of fuel vapor in there , which is heavier than air, so not much moisture laden air will be able to get into the fuel tank over the course of the off-season.

 

[Fastatv]

Re: Winterizing-Fuel Tank, Empty or Full; Stabil or Not?

Yeah. I have always left my 44 gallon tank with about 10 gallons or so of fuel in it from SEPT to about JUN the next year when I fill it up with fresh fuel.

No Stabil or other snake oils.

I do store my boat INSIDE though. Not in the water or out in the weather.

Here's what a surveyor says. (at least about what happens inside a tank)
It's not just his opinion........And he backs it up with some verifiable facts.

The Myth of Condensation in Fuel Tanks by David Pascoe: Boat Maintenance, Repairs and Troubleshooting

ymmv,


Rick

Nice link...informative. Thanks

 

[HT32BSX115]

Re: Winterizing-Fuel Tank, Empty or Full; Stabil or Not?

another thing about Dave Pascoe's article, is that the fuel tank will have a substantial amount of fuel vapor in there , which is heavier than air, so not much moisture laden air will be able to get into the fuel tank over the course of the off-season.

Yeah. I always thought it was an 'old wives tale'

I've have always been interested in the info in his article. I've noticed that the same thing applies to aircraft fuel tanks. I have always heard that one should fill aircraft tanks to prevent condensation. Years ago I worked at a small airport "FBO" (Fixed Base operator) we had many airplanes there that didn't have fuel tanks full all the time. we never did drain any water from fuel tanks that weren't full. I would think the phenomena would be more prevalent with metal tanks that are exposed like an airplane wing tank is, but it just didn't happen.

We did sometimes get a little water after a strong rain storm or when the owner "washed" his airplane.

 

[agallant80]

Re: Winterizing-Fuel Tank, Empty or Full; Stabil or Not?

I just store it where ever the needle is on the gas gauge. I stopped staball a few years back. I have never had an issue. With that said I live in NC and she is only up for about 4-5 months.

 

[stonyloam]

Re: Winterizing-Fuel Tank, Empty or Full; Stabil or Not?

Also, I have always removed all the hoses and opened the petcocks after running Marine Antifreeze through it. The last time I had it done professionally, they left the hoses on and closed the petcocks after running antifreeze through it. It was fine, of course.

To be absolutely safe you should have "removed all the hoses and opened the petcocks" before you add the antifreeze. Remember your goal is not to add antifreeze it is to remove the water.

 

[HT32BSX115]

Re: Winterizing-Fuel Tank, Empty or Full; Stabil or Not?

I just store it where ever the needle is on the gas gauge. I stopped staball a few years back. I have never had an issue. With that said I live in NC and she is only up for about 4-5 months.

Yeah. I suspect that Stabil (or other fuel "storing" substance) might be a benefit for gasoline stored a year or more........but the best bet is to store with the tank empty. That way you get fresh new gasoline when the season starts.

Loss of vapor pressure is more a problem with carbureted engines over EFI engines.......and there's NOTHING that Stabil or other snake oils can do to prevent it......The only way to stop reduction of vapor pressure is to pressurize the tank. (boats don't do that [yet])

 

[Lou C]

Re: Winterizing-Fuel Tank, Empty or Full; Stabil or Not?

I have always stored mine with whatever is in it at the end of boating season, I do put Stabil in toward the end. This is based on my yard equipment experience, where I had much less trouble getting the mower started in spring after I started using Stabil.
As far as using antifreeze, its optional really. You drain water to prevent freeze damage, you add AF to reduce corrosion. Merc says this themselves if you read their website "add antifreeze to the raw water portion of the cooling system". If your engine is raw water cooled then thats the engine and manifolds. I drain it all manually, probe the holes to make sure it drained and backfill with -100 AF with corrosion inhibitors. I do think it reduces corrosion because I do not get rusty water out the exhaust when I start it up in the spring. Do not use the suck the AF up the drive kits with a raw water cooled engine.