Storing a mower with no gas

GearHead36 · Wednesday at 3:07 PM

I have a Champion generator, which, of course, doesn't get used that often. The manual has 3 storage procedures. One for short term (up to 30 days), one for mid term (30 days to 1 yr), and one for long term (more than 1 yr). I always use the long term procedure. I say "always", but so far, that's only been two times. I bought it for hurricane Helene, so it's less than a year old. The long term procedure is:
- Open fuel valve
- Unscrew fuel drain screw on carb. This will empty the contents of the fuel tank and carb bowl through a tube out the bottom of the generator.
- Remove spark plug
- Put 1 tbsp of oil in cylinder
- Slowly pull the starter rope one time.
- Reinstall spark plug
- Screw fuel drain screw back in.

I did this after Helene, then needed it again 9 months later. I put fresh ethanol-free fuel in it, and it fired right up just like it did when new. The manual doesn't say to run it until it dies, but that wound up happening both times I've done the storage procedure. I usually run the generator until it runs out of gas, then check to see if the power has been restored. I don't know if running it until it dies makes a difference. Admittedly, it only sit for 9 months, but Champion claims that this procedure, which doesn't include putting anything in the carb, is good for long term storage. Champion also recommends ethanol-free fuel.

Auto Doc's · Wednesday at 5:57 PM

GearHead36 said:
I have a Champion generator, which, of course, doesn't get used that often. The manual has 3 storage procedures. One for short term (up to 30 days), one for mid term (30 days to 1 yr), and one for long term (more than 1 yr). I always use the long term procedure. I say "always", but so far, that's only been two times. I bought it for hurricane Helene, so it's less than a year old. The long term procedure is:
- Open fuel valve
- Unscrew fuel drain screw on carb. This will empty the contents of the fuel tank and carb bowl through a tube out the bottom of the generator.
- Remove spark plug
- Put 1 tbsp of oil in cylinder
- Slowly pull the starter rope one time.
- Reinstall spark plug
- Screw fuel drain screw back in.

I did this after Helene, then needed it again 9 months later. I put fresh ethanol-free fuel in it, and it fired right up just like it did when new. The manual doesn't say to run it until it dies, but that wound up happening both times I've done the storage procedure. I usually run the generator until it runs out of gas, then check to see if the power has been restored. I don't know if running it until it dies makes a difference. Admittedly, it only sit for 9 months, but Champion claims that this procedure, which doesn't include putting anything in the carb, is good for long term storage. Champion also recommends ethanol-free fuel.

The best part of that advice is to use Ethanol free fuel every time. It does not breakdown rapidly like Ethanol blend fuel.

dana a · Wednesday at 9:48 PM

Tiger Small Engine said:
I run 87 octane, 10% ethanol in everything from a 37 hp Vanguard to a Stihl BG85 blower, and have no problems. Keep the fuel fresh and moving, store the fuel correctly, and it is that simple. Or pay extra for stabilizer and premium fuel for no reason. Small engines are not designed to run 91 plus octane anyway. The great fuel debate continues…

Same here, that's all I use too. When I'm done for the season I start it up and close off the fuel line and when it starts to run out of gas I close the choke and that draws even more gas out of the bowl. I have never had a problem starting any of my stuff in the spring.

Tiger Small Engine · Thursday at 5:57 AM

StarTech said:
It is call Red Death for a reason.

Properly stored fuel is one key to the lack of problems. I just cranked up my Poulan chainsaw recently after it sat for over two years with fuel in it. The only problem was the plastic lever on the outside of the carb failed. It crank up up on the first pull but power as the air was not opening. New carb with improved metal link fixes plastic problem.

Now all fuels do evap and leave behind the additives which more of the problem than the ethanol; although, ethanol does have the habit of sucking moisture out of the air. Just last month I had a two cycle with harden diaphragms that the operator only use the Tru Fuel in it so that throws out the door the idea that ethanol caused the problem. Component aging was the culprit.

Plus most 4 cycle carbs are all vented to the atmosphere so fuel evaps over time easily. All carbs will need repairs over time. It is just the nature of the beast.

My old '67 Mopar 440 Hi performance engine has been running the ethanol for years without problems other than it is about worn out. My current PU V6 has over 350K on the engine. So far the only major problem with the PU was a major transmission failure at 320K and I don't think that was ethanol related, just the root cause was thrust bearing failure which destroy the whole insides.

The real fuel problem introduce by the use of ethanol fuel here was when I ran the mid grade fuel in my '79 Malibu. It a pink chalk like additive by the fuel suppliers. It would clogged the paper filter in the Holley on a regular basis. It did it so much I kept the tools and filters in my trunk at all times as I never knew when fuel filter would clog up. Switched back to the low grade fuel and the problem went away.

As I have said before, most of my customers claim to run premium, non ethanol fuel. The key to any fuel is how it is stored, and how old it is. Yes, 10% ethanol is hygroscopic ( attracts water), so storage and age of fuel is important.

Also remember that fuel, in layman’s terms, whatever the grade, has two separate combustion components. The heavier fuel that runs the engine once it is started, and the lighter, more volatile fuel that is responsible for the “bang” to get the engine started. 30-60 days is what I always recommend on 2-stroke blowers, trimmers, chainsaws, etc. for keeping fuel. Keep fuel fresh, stored well, and moving for small engines to run right. Fuel is very important to how well a small engine will run. The smaller the engine, the less forgiving it is with the quality of fuel.

sussanastallone · Thursday at 5:59 AM

Mfranch86 said:
I have a toro mower from about 2013. I stored it without any gas thinking this is better than with gas and a bottle of ethanol added in.

Well, I wound up having a family member give us a Honda mower that was in great condition and worked so over the years I used the Honda instead. The empty toro sat for YEARS.

I recently went to try and use it. Added gas and it won’t start. Since it’s been sitting for probably 10+ yrs here (w/ no gas in it), I’m thinking the carburetor needs to be replaced. will try to do that soon here.

In the meantime, is it not recommended to store a push mower without ANY gas? I was a new home owner at the time and maybe my thinking back then wasn’t correct. Ideally I’m thinking I sure I should have stored it with ethanol treated gas and at least run it a few times a year in the driveway to keep it going

Any suggestions for the future?

That’s a pretty common situation, especially with small engines that sit for long stretches. Storing the mower with an empty tank isn’t the worst idea, but over many years the carburetor parts can still dry out, gum up, or corrode, which is probably why it won’t start now. A carburetor cleaning or replacement should get that Toro running again if the rest of the engine is sound. For the future, many people recommend either draining the tank and running the carb dry before storage, or keeping a small amount of fuel in it treated with a stabilizer like Sta-Bil and starting it a couple of times a year. That way, you avoid both stale gas and dried-out internals. Sounds like with a little maintenance, you’ll be able to bring that mower back to life.

MyGrassHasCrabs · 2025-08-23T07:43:33-0400

I use a combination of these three products (in the pic below) in my fuel and have never had a problem starting engines in the spring after leaving fuel in my equipment (2 & 4 stroke) over the winter months. I use premium gas as I don't have access to leaded fuel around here.

For 2-stroke engines I always use Echo Red Armor oil. It's more expensive but worth it to me. Anecdotally, I have a 25 year old Lawn Boy push mower (original engine) that starts every spring on the first pull.

Everybody has something that works for them, this is just what has worked for me for the last several years, for what it's worth.

Chuter · 2025-08-23T08:43:14-0400

How do you "properly store" gasoline? I don't know. Everybody has their favorite witches brew of additives (or not) and a statement to "properly store" the gas, but nobody ever says how that is done. Temperature range? Container type? Sealed? Open to the air?

Honest Abe · 2025-08-23T08:49:22-0400

Chuter said:
How do you "properly store" gasoline? I don't know. Everybody has their favorite witches brew of additives (or not) and a statement to "properly store" the gas, but nobody ever says how that is done. Temperature range? Container type? Sealed? Open to the air?

I dug a small lagoon and pour it all in there now. My wife was having fits when I used her boiling pots .....

rhkraft · 2025-08-23T13:33:17-0400

I believe most carb problems are caused by storing these engines outside where moisture gets in the fuel tank and carb. Unleaded 87 octane with 10% alcohol is a blessing as it absorbed the water and prevents it from beading in the fuel tank and that dirty water from being sucked into the carb. Water seems to hold the contaminants. I have a push mower with a Briggs engine that I bought in 1990. I keep 10% alcohol gasoline in it and add Stabil in the fall. I have used this mower every year for 35 years and have never done anything to the carb. I change the oil and air filter regularly and have put 4-5 new spark plugs in it and it starts first or second pull every time. I have used this mower enough that I wore out the rear wheels to where they broke apart and I bought new wheels for it. The key is storing it inside a dry building. I keep all my gas-powered equipment in a closed garden shed. I have repaired a lot of small engines for other people and the carb problems are usually related to storing outside. Two-cycle engines do have carb problems usually the fuel pump diaphragms or dirt from storing them in pickups.

Storing a mower with no gas

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GearHead36

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dana a

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