Should I be worried? Did not fill gas tank/add fuel stabilizer.

[20Malibu06]

Very excited to have bought a very well-maintained 2006 Malibu Wakesetter XTI last spring. We're new to owning a boat. It's been out of the water since July of 2022. Stored it outdoors under a carport with cover on through the winter. Lots of rain and wind. No freezing temperatures (Santa Rosa, CA). Realizing now that we left the gas tank almost empty rather than filling it and adding stabilizer. I've read about the potential for condensation. Should we be worried? Anything we should do before running it?

[ahopkins22LSV]

It’s probably just fine. I’d top it off with fresh grass and fire it up!

[Steve B.]

I'd probably drain it by using one of those jiggle things. They work really well.

jiggle siphon

Then use that gas for the mower or whatever.

[Cole2001]

Just fill it up with premium and hit the lake! Boats sit at dealers/factories empty for longer than that without issues. Condensation was an issue in the past with metal tanks. 

[oldjeep]

Well, I never fill the tank or use stabilizer.  So, fill it up and go play.

[uk_exile]

Add half tank of highest octane you can get to refresh what's still in there and go use it.

[Woodski]

You could try to look in the tank to see if any condensation happened, if the cap was tight you should be fine.  Noting you mention almost empty, simply fill the tank with the recommended octane fuel, the octane of what is in there has not deteriorated.  Higher than recommended octane won't provide any benefit.  If you want to be really careful, use recreational fuel, or ethanol free fuel.  Basically as noted above, go have fun.

[electricjohn]

I've stored bone dry empty for 20 years with no issues.

[EchelonMike]

For extra peace of mind you can add a bottle of Dri Gas treatment that will remove any water from the old fuel, then fill it up on land before you go drop it in the lake. 99.999% chance there is not an issue.  Enjoy you new boat!  The XTi's are awesome boats, I had a 2002 for years and we loved it.

EDIT:  Link to Dri Gas Treatment:  https://www.amazon.com/MERCURY-Mercruiser-Engine-Additive-92-858069K01/dp/B0038ZWGQK

Edited April 20, 2023 by EchelonMike

[solorex]

You are over thinking this.   Fill it up and enjoy.

[20Malibu06]

Thanks everyone!! Looking forward to getting it on the lake!! Been a childhood dream to have my own boat! Appreciate the encouragement!

Edited April 20, 2023 by 20Malibu06

[oldjeep]

4 hours ago, EchelonMike said:

For extra peace of mind you can add a bottle of Dri Gas treatment that will remove any water from the old fuel, then fill it up on land before you go drop it in the lake. 99.999% chance there is not an issue.  Enjoy you new boat!  The XTi's are awesome boats, I had a 2002 for years and we loved it.

EDIT:  Link to Dri Gas Treatment:  https://www.amazon.com/MERCURY-Mercruiser-Engine-Additive-92-858069K01/dp/B0038ZWGQK

If you buy E10 - you don't have to add alcohol

[MLA]

No need to waste money on the highest premium you can find. There is no correlation between the pump octane rating and reduced BTU's of old gasoline. So 87 oct will dilute (raise the volatility of) the old gas just the same as 93 oct would. 87 and 93 have about the same BTU once ignited. The difference is in their tolerance to pre-ignition. The higher the pump octane rating, the higher its resistance to heat and igniting on its own. 

I would also suggest not filling the tank full, unless you plane to burn it all in a weekend or two. In a lot of areas, the ground tanks may still be filled with "winter" gas. Its a little more volatile then summer gas, to offset the colder winter air. Having a tank full of winter gas come late may, early june, you run the risk of vapor lock as the hotter temps will turn the fuel in the lines, to vapor. 

[formulaben]

10 hours ago, 20Malibu06 said:

Thanks everyone!! Looking forward to getting it on the lake!! Been a childhood dream to have my own boat! Appreciate the encouragement!

You're in the right place.  Nothing beats having your own boat...welcome to the Crew!!

[electricjohn]

18 hours ago, MLA said:

No need to waste money on the highest premium you can find. There is no correlation between the pump octane rating and reduced BTU's of old gasoline. So 87 oct will dilute (raise the volatility of) the old gas just the same as 93 oct would. 87 and 93 have about the same BTU once ignited. The difference is in their tolerance to pre-ignition. The higher the pump octane rating, the higher its resistance to heat and igniting on its own. 

I would also suggest not filling the tank full, unless you plane to burn it all in a weekend or two. In a lot of areas, the ground tanks may still be filled with "winter" gas. Its a little more volatile then summer gas, to offset the colder winter air. Having a tank full of winter gas come late may, early june, you run the risk of vapor lock as the hotter temps will turn the fuel in the lines, to vapor. 

The difference between winter and summer gas is the ratio of butane and pentane additive. Butane (a more stable C4 hydrocarbon) in the summer and Pentane (a less stable C5 hydrocarbon) in the winter.