Why Use Sea Foam Fuel Additive in a Lawn Mower?


You’ve probably been stuck trying to start your mower the following mowing season only to find out it won’t start. A big culprit to mowers not starting after sitting a while is stale gasoline. Gasoline does not have a long shelf life and needs to be used within 30 days unless you add a fuel stabilizer.

Sea Foam fuel stabilizer can be used in any gas or diesel combustible engine and fuel system. Sea Foam is a petroleum based product without harsh chemicals making it safe to use in your engine or fuel system.

Below, we’ll cover how Sea Foam can help with in a mower’s motor and fuel system, as well as whether or not the solution should be used with your lawn mower and how much you should use. 

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Can You Use Sea Foam Fuel Additive in a Lawn Mower?

Sea FoamOpens in a new tab. is a brand of fuel additive; Some of the improvements you can expect to see by using a Sea Foam product could be:

  • Reduced moisture in the fuel
  • Stabilizes fuel for up to two years
  • Cleans carburetor liquifying deposits and residues built up on needles, seats, and float bowls.
  • Improved performance
  • Cleans intake valves

In addition to cleaning the built-up deposits and dirt from your combustion engines, using Sea Foam as a fuel additive has been shown to has also been shown to improve performance and extend the overall lifespan of engines.

Sea Foam has been on the market for over 70 years. Sea Foam is a petroleum based product so you do not have to worry about the solution damaging your mower’s engine; it’s designed to prolong your motor’s life.

Why Use Sea Foam in a Lawn Mower?

Sea Foam stabilizes fuel for up to two years. There are three reasons why you would want to use an additive like Sea Foam in your lawn mower.

  1. Valve Seat Erosion: The valves of a combustion engine open and close to allow air into the cylinders and the exhaust to exit the cylinders. Over time this can become damaged and eroded by built-up particulates and debris. Sea Foam helps clean and remove this debris, ultimately extending the life of the valves.
  2. Damaging Effects of Ethanol: In addition to debris and particulates from the air intake, the ethanol present in modern-day gasoline carries corrosive properties. These corrosive properties affect metals such as iron and steel and leave behind salt deposits which can clog your fuel pump. Read more about the effects of ethanol and the type of fuel to use in your gas powered lawn mower here.
  3. Reduce moisture in the fuel system

How to Use Sea Foam on Lawn Mowers

One of the problems gasoline has is that it leaves behind a gummy corrosive residue that can cause blockages and drain the performance of your engine (see above). This residue is worsened if left sitting for long periods, during the winter season, for example. So, in these instances, a fuel system cleaner can help. 

A 16 ounce can of Sea Foam can treat up to 16 gallons of fuel. Generally, to use as a fuel system cleaner and stabilizer on your lawn mower:

  1. Fill a 1 gallon can of gasoline with 1 gallon of gas. 
  2. Then add the appropriate amount of cleaner to the can
    – 2 ounces for every gallon when cleaning your fuel tank. Using more than 2 ounces is okay. The more you use, the better the solution cleans.
    – 1 ounce for every gallon when using as regular fuel maintenance

I recommend using Sea Foam in each tank of fuel.

Can You Use Fuel System Cleaner in a Lawn Mower?

A gas-powered lawn mower operates the same as any other gasoline-powered engine. As the engine is running, various dirt particles will enter into the mix through the air intake. You can clean this the hard way by manually taking the engine apart to clean it, or the expensive way by taking it to a professional to do so. But the easiest way to clean out this excess debris is by using a fuel system cleaner. 

Fuel system cleaners like Sea Foam remove this excess dirt and debris that accumulates in the engine over time. Keeping the engine clean keeps the fuel itself clean, which improves the performance of the engine. 

Solutions You Shouldn’t Use on Lawn Mowers

Although many fuel system cleaners can be safely used with a lawn mower, there are a few solutions that shouldn’t be used at all. Here is a product that is not recommended to be used with a lawn mower:

  1. Any Additive Targeting a Diesel Engine: This includes Diesel System Cleaner and a Diesel Emissions Reducer. Avoid these solutions if you own a gas or petrol-powered lawn mower. 

Other Fuel System Cleaners That Work on Lawn Mowers

While Sea is perfectly safe and effective to use for your lawn mower (and any combustion engine for that matter), there are a few alternatives that you could consider as well:

  1. Archoil AR 6200Opens in a new tab.: Archoil is mainly intended for diesel engines but can be used with gas engines too. It acts as a stabilizer as well as a detergent.
  2. Lucas Safeguard Ethanol Fuel ConditionerOpens in a new tab.: This is an older product that acts as a lubricant and a detergent to help combat the natural deposit build-up caused by ethanol.
  3. STA-BIL OriginalOpens in a new tab.: This is again an older product. It’s primarily a fuel stabilizer that can, again, extend the life of fuel for up to two years. It’s also a well-rounded product that helps prevent corrosion and remove water build-up, but with the increased adoption of ethanol fuels, its effectiveness has waned compared to a competitor like Seafoam.  

Related Items

For information on lawn mower fuel leaks read: “10 Reasons Your Lawn Mower Could Be Leaking Gasoline“.

Water in your fuel tank? Check out “Why Your Mower Won’t Start After Leaving In the Rain“.

Powered Equipment Team

We're just a guy and a girl obsessed with outdoor power equipment! We are excited to share the knowledge and tips we have learned over our combined 55 years in the power equipment industry. We have both ran equipment dealerships and took pleasure in helping our customers everyday providing equipment repair, parts, purchasing, and business tips to our residential and commercial clients. We hope our blog will help you with your next purchase, repair, or project.

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