Last summer, my trusty old lawnmower refused to start, leaving me with a jungle-like backyard. After much frustration, I discovered the culprit: old gas. This post will explore how old gas can affect your lawnmower and what you can do to avoid this frustrating situation. You’ll learn how to troubleshoot starting problems, maintain your mower, and save yourself time and money.
How Old Gas Damages a Lawn Mower
Old gasoline degrades over time, losing its volatility and becoming less effective at combusting. This section explains the chemical processes involved and their impact on your lawnmower’s engine.
The Chemistry of Deterioration
Gasoline is a complex mixture of hydrocarbons. Over time, these hydrocarbons evaporate, leaving behind heavier, gummier residues. This process is accelerated by exposure to air, light, and heat.
- Evaporation: The lighter, more volatile components evaporate first, leaving behind a less flammable mixture. This reduces the engine’s ability to ignite properly. This process can be significantly impacted by storage conditions, with higher temperatures leading to faster evaporation rates.
- Oxidation: Oxygen in the air reacts with the hydrocarbons, forming gums and resins. These sticky substances clog fuel lines, carburetors, and fuel filters, restricting fuel flow to the engine. The resulting blockage prevents sufficient fuel from reaching the combustion chamber, leading to starting difficulties or complete engine failure.
- Polymerization: Some hydrocarbons link together to form larger molecules, further contributing to the gum and varnish buildup. This thickening of the fuel further restricts flow, hindering the engine’s ability to receive the necessary fuel for ignition.
Consequences of Using Old Gas
Using old gas can lead to a variety of problems, ranging from difficulty starting to complete engine failure. This section provides specific examples of how old gas manifests itself in a lawnmower engine.
- Difficult Starting: The engine may crank but fail to ignite or sputter and die repeatedly. This is often the first sign that the fuel is degraded.
- Poor Performance: Even if the engine starts, it may run poorly, with reduced power and increased smoking. The incomplete combustion of the old fuel leads to inefficient performance and the release of harmful emissions.
- Engine Damage: In severe cases, old gas can cause irreparable damage to the fuel system and engine components. The gummy residue can clog fuel injectors, damage the carburetor, and even corrode internal engine parts.
Identifying the Problem: Is It Old Gas?
This section guides you through diagnosing whether old gasoline is responsible for your lawnmower’s starting issues, differentiating it from other potential problems.
Troubleshooting Your Lawn Mower
Before assuming old gas is the culprit, let’s rule out other common causes. Systematically checking these issues helps pinpoint the root cause and avoid unnecessary repairs.
- Spark Plug: A fouled or damaged spark plug prevents ignition. Check the plug for damage and clean or replace it if necessary. Regularly checking and replacing spark plugs is crucial for engine performance and longevity.
- Air Filter: A clogged air filter restricts airflow to the engine, hindering combustion. Clean or replace the air filter for optimal performance. A dirty air filter can significantly impact fuel efficiency and engine power.
- Fuel Filter: A clogged fuel filter prevents fuel from reaching the engine. Check for clogs and replace the filter. This is especially important if you suspect old gas is the problem.
The Smell Test and Visual Inspection
Sometimes, the simplest methods are the most effective. A quick sniff and visual check can provide valuable clues about the condition of your fuel.
If the gasoline smells stale or varnish-like, it’s a strong indication of age and degradation. Similarly, inspecting the fuel lines and carburetor for gummy residues provides visual confirmation of the problem. A visual inspection can help you identify potential leaks and clogs in the fuel system.
Preventing Old Gas Problems: Proper Fuel Storage and Maintenance
This section emphasizes preventative measures to avoid the complications associated with degraded gasoline and extend the lifespan of your lawnmower.
Proper Fuel Storage
Storing gasoline correctly is critical in preventing degradation. Using proper containers and storage techniques helps maintain fuel quality.
- Use Approved Containers: Always store gasoline in approved, sealed containers designed for fuel storage. Improper containers can lead to leaks, spills, and vapor emissions.
- Store in a Cool, Dark Place: Keep gasoline containers in a cool, dry, and well-ventilated area, away from direct sunlight and heat sources. Heat accelerates the evaporation and oxidation processes.
- Don’t Overfill: Leave some space in the container to allow for expansion and prevent spills. Overfilling can lead to pressure buildup and potential leaks.
Regular Lawn Mower Maintenance
Regular maintenance prevents small problems from becoming major headaches. A well-maintained lawnmower is less susceptible to fuel-related issues.
- Empty the Fuel Tank: Before storing the mower for extended periods, drain the fuel tank completely to prevent the buildup of old gas. This simple step significantly reduces the risk of fuel-related problems.
- Use Fuel Stabilizer: Adding a fuel stabilizer to the gasoline helps slow down the deterioration process, extending the usable life of the fuel. Fuel stabilizers are readily available at most hardware stores.
- Run the Engine Dry: After using the lawnmower, run the engine for a few minutes to remove any remaining fuel from the carburetor and fuel lines. This minimizes the amount of old fuel left in the system.
Dealing with Old Gas: Cleaning and Repair
This section details how to address the problem if old gas has already damaged your lawnmower’s fuel system, including cleaning methods and potential repair needs.
Cleaning the Fuel System
Cleaning the fuel system can often restore functionality, but sometimes professional help is necessary.
- Drain the Fuel Tank: Begin by draining the old fuel from the tank. Dispose of it properly according to local regulations.
- Clean the Fuel Filter: Inspect and clean or replace the fuel filter. A clogged filter can restrict fuel flow even after fresh gas is added.
- Clean the Carburetor: If the carburetor is clogged, it may need to be disassembled, cleaned, and reassembled. This often requires specialized tools and knowledge. For complex carburetors, professional help is recommended.
Repairing Engine Components
Extensive damage may require professional repair or replacement of damaged parts.
In cases of severe gumming or varnish buildup, you might need to replace fuel lines, fuel injectors (if applicable), or even parts of the engine. A mechanic can diagnose the extent of the damage and recommend the necessary repairs.
FAQ
Can old gas ruin a lawn mower engine completely?
Yes, extremely old and degraded gasoline can cause significant damage to a lawn mower engine, leading to costly repairs or even the need for engine replacement. The gummy residue can clog critical components and cause corrosion.
How long can gasoline sit in a lawn mower before it goes bad?
Gasoline begins to degrade after about 30 days, losing its volatility and forming harmful residues. The rate of degradation is influenced by temperature and exposure to air and light.
What are the signs of old gas in a lawn mower?
Signs include difficulty starting, poor performance, sputtering, smoking, and a stale or varnish-like smell from the fuel.
Can I just add fresh gas to old gas in my lawn mower?
While it might seem like a quick fix, it’s generally not recommended. Mixing old and new gasoline might not solve the issue, and could even worsen the problem by further clogging the fuel system.
How do I properly dispose of old gasoline?
Check with your local waste management authority or a local auto parts store for the best method for disposing of old gasoline in your area. Never pour old gasoline down the drain or into the environment.
Can I use a fuel additive to clean out old gas?
Yes, some fuel additives are formulated to help clean fuel injectors and carburetors and break down gum and varnish. Use according to package directions and consider professional help for severe cases.
How often should I change my lawn mower’s fuel?
It’s best practice to use fresh gasoline and to empty the fuel tank before long-term storage. Using a fuel stabilizer can extend the gasoline’s usable life.
Final Thoughts
Addressing the issue of old gas in your lawn mower is crucial for both its performance and longevity. By understanding the causes of fuel degradation, implementing proper storage techniques, and performing regular maintenance, you can significantly reduce the risk of encountering starting problems. Remember, regular maintenance and using fresh fuel are your best defense against costly repairs and frustrating downtime. Don’t let old gas ruin your next lawn-care session – take preventative measures today!
