Why I Store My Jet Ski Nearly Empty For The Winter

I don’t know how the topic of how much gas you should store in your boat has become such a hotly debated topic, but it has?

Typically, I see this question arise around winter, when people leave their jet skis for months. Though, it’s still a problem for anyone who stores for long periods of time, no matter the season.

So, what should you do? Let’s talk about it.

What I do

The common answer for storing gas in any boat is to have it full and add fuel stabilizer.

On the other hand, I do the opposite, but I still add stabilizer.

When I put away my Sea-Doo Spark, I like having the gas tank at 1 or 2 bars on the gas gauge.

The honest truth is that both ways are fine, but I consider having a little gas to be slightly better.

Let’s go over the reason for both and why, overall, nearly empty is better.

Full Bars

2006 RXT 215 display showing gas and hours

The reason many in the boating world like to store their fuel tanks filled to the brim of gasoline is that there are fewer chances for water to get in.

Boats work in wet conditions and are prone to water getting in, it’s worsened by ethanol in gas. A fuller tank reduces air and water getting in, preventing fuel issues.

With boats having large tanks, 30 or 50 gallons or even larger gas tanks, you can see how the chances of water is so much greater. (More fuel, more that can attract water).

Jet skis are a bit different, they have at most 20 gallon gas tanks, with some as little as 5 gallons. Even with smaller tanks, I don’t see having a full tank as the better option when storing any boat.

This Way Is Better:

When I say near empty, I mean one or two bars on the display, or about one or two gallons. Most of the time, it’s whatever was left after the last ride of the season, which is often one or two bars. I don’t remove any fuel, but instead try to ride my Spark until I get the fuel tank low enough.

These are the reasons why storing your jet ski near empty is better:

  1. Cheaper.
  2. If the fuel goes bad, just add more fresh gas.
  3. Safer.
  4. Cuts down on theft.
  5. Cuts down on waste.

Allow me to explore each point in more detail on why it’s the better option for winter storage.

1. Cheaper

Gas station gas pump

If you’re storing for winter, only add fuel stabilizer when the tank is low, around one or two bars on the display, but ensure there’s at least 1 gallon of gas in the tank.

Leaving some fuel is important for parts like the fuel pump.

Storing it low on fuel saves on costs and requires less stabilizer due to the lower gas in the tank. It’s a win-win!

2. Bad Fuel

gas station gas pump for non-ethanaol

The whole reason someone would keep the tank filled up is to keep water out, so it doesn’t go bad.

If there is not a lot in the fuel tank, there isn’t a lot to go bad.

It’s all about dilution.

When the season starts back up, just fill up with some premium. If you kept it low, then the 1 gallon of gas that MAY have gone bad is diluted with the 4 to 19 gallons of fresh fuel!

On the other hand, if you keep it near filled up and that goes bad, you can’t dilute it. You must suck out the old stuff and then add new fuel. (And removing gas is dangerous).

3. Safer

safety gas can out side

People put their machines either in their garage or near their home, and something about a 5 to 20 gallons of gas sitting that close to my home worries me.

Sure, people keep their gas cans, cars and trucks in garages and have no problem, but why have something else to worry about?

If one option is cheaper, safer, and overall easier, I’m going to go with that one.

4. Cuts Down On Theft

This may not affect everyone, but when gas prices get high, people get bold.

Extracting gas from a vessel is relatively easier compared to a car or truck. Personal watercraft typically lack a mechanism to prevent siphoning of gas. Moreover, removing the seat provides direct access to the fuel, facilitating the process.

Most can hold up to 20 gallons of gas, that is about two cars worth of gasoline!

Though I will give a point to the people who leave a boat filled to the top of gas as it will make for a great emergency backup gas supply to run a generator.

To see more about security and things you can do, go here!

5. Cuts Down On Waste

If you’re storing it full of gas during the winter, you still run the risk of that gas going bad. The longer the thing sits, the greater the chances of the gas going bad.

Bad gas is hard to dispose of; cars and boats won’t run well on it, but it can be used for lawn mowers.

You can’t dump the gas either, it must be disposed of properly and by a professional. Gas vapors are no joke, and sucking it back out is dangerous!

As talked about in point 2, I rather have a little gas that goes bad and then add fresh fuel to dilute it. It’s easier to dilute a little bit of gas than to get rid of a lot of bad fuel.

Personal Preference

lake norman water view nice day

At the end of the day, it’s more about personal preference and what is right for you.

There is at least one good point about storing near filled up of gas and that is for an emergency fuel supply, but overall, I think it’s not worth it.



I started working at a power sports dealership in 2007, I worked in parts, service counter, and as a technician before moving to sales in 2013. I created in 2014 to answer common watercraft questions I would get from people. Now managing the site full-time, I continue to provide advice and web tools for my readers about watercraft. I've owned several watercraft, with a Sea-Doo Spark as my current main PWC.


  1. I had always heard that keeping gas tanks 80% (ish) full in the off season helped to keep seals and other components “wet” so they didn’t dry out. Kinda like a cork in a wine bottle or running the dishwasher every once in a while. You don’t want those things going a long time without being used or the cork/seals dry out and then the first time you go to use them you have a huge (and costly) mess.

    • That’s a fair point, but I’ve never seen this be a huge problem. I’ve gotten jet skis out of crates that have been sitting for years with no gas in them and everything be fine. A lot of the problems I see are due to ethanol in gas, that is more likely to destroy seals and lines more than keeping them dry.


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