The warm weather is here, and it’s time to fire up the lawn mower. But what happens when you discover a can of gas in the back of your shed, with a date from last summer, or even further back in time? Can you use this old gas in your lawn mower, or is it best to just dispose of it and start fresh? This article will explore the potential problems associated with using old gas in your lawn mower, the signs that your gas has gone bad, and what you can do to prevent this issue in the future.
The short answer is: you probably shouldn’t. Old gas can cause numerous problems in your lawn mower, from engine sputtering and difficulty starting to serious damage to the fuel system. This article will go into more detail about the reasons why.
The Effects of Old Gas on Your Lawn Mower
Gas is a volatile substance that degrades over time, especially when exposed to air and sunlight. As it ages, the following changes occur:
Gas Breakdown:
- Evaporation: Gas evaporates over time, leaving behind a more concentrated mixture of heavier hydrocarbons.
- Oxidation: Oxygen reacts with the gas, forming gum, varnish, and other deposits.
- Water Contamination: Over time, water can condense in the fuel tank, which can mix with the gas and cause corrosion.
Problems with Old Gas
These changes in gas composition can lead to several problems in your lawn mower engine:
1. Difficulty Starting
- Fuel System Blockage: Gum and varnish can clog fuel lines, filters, and the carburetor, making it difficult for the engine to receive enough fuel.
- Reduced Fuel Volatility: Older gas evaporates less readily, making it harder for the engine to ignite the fuel.
2. Engine Sputtering and Poor Performance
- Incomplete Combustion: Degraded gas doesn’t burn as efficiently, leading to uneven power delivery and potential engine damage.
- Fuel System Corrosion: Water contamination in the gas can cause corrosion in the fuel tank, lines, and carburetor.
3. Engine Damage
- Carburetor Damage: Gum and varnish buildup in the carburetor can damage delicate parts like the needle valve and jets.
- Fuel Pump Damage: The fuel pump may be unable to properly pump the thickened fuel.
How to Tell if Your Gas is Bad
There are a few visual cues that can help you determine if your gas is old and unusable:
1. Smell
Fresh gasoline has a distinctive, strong odor. If the gas smells sour or stale, it’s likely too old.
2. Color
Fresh gas is typically clear or slightly yellowish. If the gas has a milky or reddish appearance, it’s likely contaminated with water or has degraded significantly.
3. Sediment
If you see sediment at the bottom of the gas can, it’s a sure sign the gas is no longer good.
Preventing Old Gas in Your Lawn Mower
It’s better to prevent old gas than to deal with its consequences. Here are some tips:
- Use a Fuel Stabilizer: Add a fuel stabilizer to your gas tank, following the manufacturer’s instructions. Fuel stabilizers help prevent gas from degrading and extend its usable life.
- Buy Small Amounts: Only purchase the amount of gas you need for your immediate use. Avoid storing large quantities of gas for long periods.
- Empty Your Tank at the End of the Season: Before storing your lawn mower for the winter, drain the gas tank and run the engine until it stops to clear the fuel lines.
What to Do with Old Gas
If you find yourself with old gas, you have a few options:
- Dispose of It Properly: Never pour old gas down the drain or into the ground. Many municipalities have hazardous waste disposal programs for gasoline. Check with your local waste management agency for information.
- Use It in a Different Application: Some people use old gas for non-critical tasks like cleaning or for generators that aren’t critical for immediate use. However, proceed with caution as it may still cause damage.
Conclusion
Using old gas in your lawn mower can lead to various problems, including difficulty starting, engine sputtering, and even engine damage. To avoid these issues, buy small amounts of gas, use fuel stabilizer, and empty your tank at the end of the season. If you do find yourself with old gas, dispose of it properly to protect the environment. By taking these steps, you can ensure that your lawn mower is ready to go when you need it.
FAQs
1. How long can gas stay in a lawn mower before it goes bad?
It’s generally recommended to use gasoline within 30 days of purchase. However, this can vary depending on the quality of the gasoline and the storage conditions. Gasoline degrades over time due to a process called oxidation. This leads to the formation of gums and varnishes that can clog fuel lines and carburetors, making it difficult for your lawn mower to run smoothly.
If you’re storing gasoline for longer periods, it’s crucial to use a fuel stabilizer. Fuel stabilizers prevent the oxidation process, keeping gasoline fresh for up to a year. Storing gasoline in a cool, dark place can also help extend its shelf life.
2. What happens if you use old gas in your lawn mower?
Using old gas in your lawn mower can lead to various issues. The most common problem is difficulty starting the mower due to clogged fuel lines or a fouled carburetor. Additionally, you might experience a decrease in engine power, uneven engine running, or even a complete engine failure.
In extreme cases, old gas can damage the engine itself. The gums and varnishes created by the degradation process can accumulate within the engine, leading to wear and tear on critical components like pistons and valves. This can ultimately require expensive repairs or even a complete engine replacement.
3. What are the signs of bad gas in a lawn mower?
Several signs can indicate that your lawn mower is running on old gasoline. The most common symptom is difficulty starting the mower. It might crank for a long time before starting, or it might start but sputter and die immediately. Another indication is a decrease in engine power, causing the mower to run slower or struggle to cut grass.
You might also notice a change in the engine sound, with uneven running or a knocking noise. A strong gasoline smell can also be a sign of bad gas, especially if it’s accompanied by a build-up of moisture in the fuel tank.
4. Can you clean old gas out of a lawn mower?
While it’s best to avoid using old gas in the first place, you can often clean it out of a lawn mower. The first step is to drain the old gasoline from the fuel tank. Then, you need to remove the fuel filter and clean or replace it. You may also need to clean the carburetor, especially if it’s clogged with gum and varnish.
If you’re not comfortable cleaning the carburetor yourself, it’s best to take the lawn mower to a qualified mechanic. They can professionally clean and tune up the carburetor, ensuring it operates efficiently.
5. Can you mix old gas with new gas?
While mixing old gas with new gas might seem like a good solution, it’s not recommended. The old gas will still contain the harmful gums and varnishes that can damage your lawn mower. Even a small amount of old gas in a tank of fresh gas can lead to problems over time.
If you have a small amount of old gas left, it’s best to use it up in a gas-powered tool that’s less sensitive to fuel quality, like a chainsaw or weed trimmer. Avoid using it in your lawn mower or other sensitive equipment.
6. How do you prevent old gas from forming in your lawn mower?
The best way to prevent old gas from forming is to use fresh gasoline regularly and avoid storing large quantities of gas for extended periods. If you have to store gasoline for longer periods, use a fuel stabilizer to prevent oxidation and keep the gasoline fresh.
It’s also important to store gasoline properly in a cool, dark place. Avoid storing gasoline in direct sunlight or extreme temperatures, as this can accelerate the degradation process.
7. Can you use ethanol-free gas in your lawn mower?
Using ethanol-free gasoline in your lawn mower can be beneficial. Ethanol can absorb moisture from the air, leading to phase separation in gasoline. This can cause problems in small engine fuel systems, leading to clogged fuel lines and carburetors.
Ethanol-free gasoline is typically more expensive than regular gasoline. However, it offers better storage stability and is less prone to causing problems with small engines. If you’re concerned about using old gas in your lawn mower, using ethanol-free gasoline can help prevent these issues.