As the crisp autumn air settles in and the last leaves are swept from your lawn, it’s time to consider the proper storage of your trusty lawn mower. One of the most frequently debated topics among homeowners is what to do with the fuel tank. The question echoes in garages and sheds across the country: can I leave gas in my lawn mower over winter? The answer, as with many things in life, isn’t a simple yes or no. It depends on a few key factors, and understanding them can save you a significant headache (and expense) come spring.
The Science of Stored Gasoline
Gasoline is a complex mixture of hydrocarbons, and unfortunately, it’s not designed for long-term storage. Over time, gasoline degrades. This degradation process is accelerated by several factors, including exposure to air, changes in temperature, and the presence of ethanol, which is a common additive in modern gasoline.
Ethanol is hygroscopic, meaning it attracts and absorbs moisture from the air. This absorbed water can then separate from the gasoline, creating a layer of water at the bottom of the fuel tank. This water-contaminated fuel can lead to a host of problems, from engine sputtering to serious internal damage. Furthermore, the lighter, more volatile components of gasoline evaporate over time, leaving behind a thicker, gum-like residue. This residue can clog fuel lines, carburetors, and fuel injectors, preventing the engine from starting or running smoothly.
The Risks of Leaving Untreated Gas in Your Mower
Leaving untreated gasoline in your lawn mower for an extended period over winter can lead to several undesirable outcomes. The most common and frustrating is difficulty starting the mower in the spring. The degraded fuel simply won’t ignite efficiently, or the clogged fuel system will prevent fuel from reaching the engine.
Beyond just a no-start situation, the gum and varnish deposits can corrode metal components within the fuel system. This corrosion can weaken parts, lead to leaks, and ultimately require costly repairs. The presence of water can also cause rust within the fuel tank and lines, further exacerbating the problem. Imagine pulling your mower out of storage, eager to get your lawn back in shape, only to be met with a sputtering engine and the realization that you’ve potentially damaged your equipment. This is the gamble you take when leaving untreated fuel.
The Benefits of Proper Fuel Stabilization
The good news is that these issues can be largely avoided with a little foresight and preparation. The primary solution is to use a fuel stabilizer. A fuel stabilizer is an additive that extends the life of gasoline by preventing oxidation and separating the ethanol from the water.
When added to the fuel tank before storage, a stabilizer essentially “freezes” the gasoline in its current state, preventing the volatile components from evaporating and the ethanol from absorbing moisture. This ensures that the fuel remains viable for much longer periods, often up to 12-24 months, depending on the product and storage conditions. Using a stabilizer is a relatively inexpensive preventative measure that can save you significant money and frustration in the long run.
The “Drain or Stabilize” Debate
Many experienced lawn care enthusiasts and manufacturers recommend a two-pronged approach to winter storage: either drain the fuel tank completely or fill it and add a fuel stabilizer. Each method has its proponents and its advantages.
The Draining Method
The draining method involves siphoning or running the engine until the fuel tank is completely empty. This eliminates the risk of fuel degradation and gum formation altogether.
Pros of Draining
- Eliminates all fuel-related storage issues.
- No reliance on fuel stabilizer effectiveness.
Cons of Draining
- Can be messy and requires proper disposal of old gasoline.
- Some argue that a completely empty fuel tank is more susceptible to internal rust due to moisture accumulation.
To effectively drain the fuel tank, you can either run the engine until it sputters and dies, or you can use a siphon pump to remove the fuel. If you choose to run the engine dry, ensure you do so in a well-ventilated area, as the exhaust fumes can be harmful. After draining, it’s a good practice to start the engine again for a few seconds to clear any residual fuel from the carburetor. Remember to dispose of the drained gasoline responsibly. Many local waste management facilities accept used gasoline for proper recycling.
The Stabilizer Method
The stabilizer method involves filling the fuel tank to near capacity and adding the recommended amount of fuel stabilizer. The engine is then run for a few minutes to allow the stabilized fuel to circulate through the entire fuel system, including the carburetor.
Pros of Stabilizer Method
- Keeps the fuel system lubricated and protected from moisture.
- Less messy than draining.
- Easier to start the mower in spring as the fuel is still fresh.
Cons of Stabilizer Method
- Relies on the quality of the fuel stabilizer and proper mixing.
- If the tank is not filled adequately, condensation can still form.
Filling the tank almost completely is crucial when using a stabilizer. This minimizes the amount of air in the tank, thereby reducing the potential for condensation to form and mix with the fuel. When adding the stabilizer, follow the manufacturer’s instructions precisely. Over- or under-dosing can be less effective. After adding the stabilizer, start the engine and let it run for about 5-10 minutes. This ensures that the stabilized fuel makes its way into the carburetor and coats all internal fuel components. This is a critical step that many people overlook, rendering the stabilizer less effective.
Factors to Consider When Making Your Decision
Several factors can influence your choice between draining and stabilizing. The length of your winter storage period is a significant consideration. If you live in a region with a very short mowing season, and your mower will be in storage for 6-8 months, proper preparation is paramount. If your storage period is shorter, say 2-3 months, the risk might be slightly lower, but proper preparation is still advisable for optimal performance.
The type of gasoline you use also plays a role. Gasoline with a higher ethanol content (like E10 or E15) is more prone to degradation and water absorption than pure gasoline or fuel with lower ethanol content. If you can reliably source ethanol-free gasoline, the risks associated with leaving it in your mower are somewhat reduced, but not eliminated. However, ethanol-free gasoline is becoming increasingly difficult to find for everyday consumers.
Your mower’s fuel system design is another point to consider. Mowers with carburetors are particularly susceptible to gumming and clogging. Modern mowers with fuel injection systems may be slightly more resilient, but they are not immune to the effects of degraded fuel.
Best Practices for Winter Lawn Mower Storage
Regardless of whether you choose to drain or stabilize, there are other best practices that will ensure your lawn mower emerges from winter ready for action.
Cleanliness is Key
Before putting your mower away, give it a thorough cleaning. Remove all grass clippings, dirt, and debris from the deck, engine, and wheels. This prevents corrosion and makes it easier to inspect for any potential issues in the spring. A good wash and dry will go a long way.
Oil Change and Maintenance
Winter is the perfect time to perform an oil change. Fresh oil lubricates the engine components and helps prevent moisture buildup. Check and change the spark plug, air filter, and blade as needed. A well-maintained mower will perform better and last longer.
Battery Care
If your mower has an electric start, pay attention to the battery. It’s advisable to disconnect the battery terminals to prevent any slow discharge. For longer storage periods, consider using a battery tender to keep the battery charged and prolong its lifespan. Store the battery in a clean, dry place, ideally at a moderate temperature.
Storage Location
Store your lawn mower in a clean, dry, and protected environment, such as a garage, shed, or covered patio. Avoid storing it directly on the ground, as this can lead to rust and moisture problems. Placing it on wooden blocks or a pallet can help.
The Verdict: Is It Worth the Risk?
In conclusion, while it might be tempting to skip the fuel preparation step for your lawn mower, the risks associated with leaving untreated gasoline in the tank over winter are significant. The potential for fuel degradation, gum formation, and component corrosion can lead to expensive repairs and a frustrating start to the mowing season.
The most prudent approach is to either thoroughly drain the fuel tank or, preferably, fill it and add a quality fuel stabilizer. By investing a little time and a small amount of money in proper winterization, you are safeguarding your investment and ensuring that your lawn mower will be ready to tackle your yard work when spring arrives. Don’t let a simple oversight lead to a costly problem; prepare your mower for its winter slumber with confidence.
Why is it important to prepare a lawn mower for winter storage?
Proper winter storage prepares your lawn mower for optimal performance in the spring. Leaving fuel in the tank can lead to the formation of gummy deposits and varnish, which can clog the carburetor and fuel lines. This can result in difficult starting and poor engine performance when you next need to use the mower.
Additionally, stagnant fuel can absorb moisture from the air, leading to corrosion within the fuel system and tank. Addressing these potential issues before winter sets in ensures a smoother transition into the next mowing season, saving you potential repair costs and frustration.
What happens if I leave gasoline in my lawn mower over winter without taking any precautions?
If you leave gasoline in your lawn mower over winter without any precautions, several detrimental effects can occur. The fuel itself will degrade over time, oxidizing and breaking down into less volatile components. This degradation can lead to a loss of octane rating and the formation of harmful deposits within the engine’s fuel system.
These deposits are the primary culprits behind starting problems and rough running in the spring. They can clog the carburetor jets, gum up fuel injectors, and even damage internal engine components if left unchecked for extended periods.
What is the recommended procedure for preparing a lawn mower for winter storage?
The most recommended procedure for preparing a lawn mower for winter storage is to drain all the fuel from the tank and run the engine until it stalls. This ensures that any residual fuel in the carburetor and fuel lines is burned off, preventing the formation of deposits. After draining and running, it’s advisable to use a fuel stabilizer.
The fuel stabilizer should be added to a small amount of fresh gasoline, which is then added to the tank and run through the engine for a few minutes. This coats the internal fuel system components with the stabilizer, protecting them from corrosion and gumming.
What are the pros and cons of using a fuel stabilizer versus draining the gas?
Using a fuel stabilizer offers a significant advantage by preventing the degradation of fuel and protecting the fuel system from corrosion and gumming. It’s a less labor-intensive process than completely draining the mower, making it a convenient option for many users. The stabilizer also ensures that the fuel remains viable for longer periods, even if you decide to use it in the spring.
However, the primary con of relying solely on a stabilizer is that it doesn’t completely remove all residual fuel from the carburetor. While it minimizes the risk, a small amount of fuel remaining can still potentially cause minor issues. Draining the gas completely eliminates this risk but requires more effort and might lead to a very dry carburetor, which could also require some attention in the spring.
What are the risks associated with storing a lawn mower with a full tank of gas?
Storing a lawn mower with a full tank of gas carries several risks, primarily related to fuel degradation. Over time, gasoline loses its volatility and can form gummy residues and varnish, which can clog vital parts of the fuel system, especially the carburetor. This can lead to a mower that’s difficult to start or runs poorly when you need it again.
Furthermore, gasoline is a volatile substance, and storing it in a tank for extended periods, especially in fluctuating temperatures, increases the risk of vapor buildup and potential safety hazards. While modern mowers have safety features, it’s always best to minimize the amount of volatile fuel stored unnecessarily.
Can I use a fuel stabilizer with ethanol-based gasoline?
Yes, you absolutely can and should use a fuel stabilizer with ethanol-based gasoline, especially for winter storage. Ethanol is hygroscopic, meaning it attracts and absorbs moisture from the air. This moisture can separate from the gasoline and settle at the bottom of the fuel tank, leading to corrosion and phase separation, where the ethanol and water become a distinct layer.
Fuel stabilizers are specifically designed to combat these issues. They help to prevent phase separation by keeping the ethanol mixed with the gasoline and also provide anti-corrosion properties that protect the fuel system components from damage caused by the absorbed moisture.
What are the signs that my lawn mower’s fuel system might have issues from improper winter storage?
Several signs can indicate that your lawn mower’s fuel system has suffered from improper winter storage. The most common symptom is difficulty starting the mower in the spring, often requiring multiple pulls or prolonged cranking. Even if it does start, the engine may run roughly, sputter, or stall unexpectedly.
You might also notice a lack of power, poor acceleration, or an uneven idle. Visually inspecting the fuel and fuel lines for any gummy residue, varnish, or signs of corrosion can also provide clues. If you detect a stale or foul odor from the fuel, it’s a strong indicator of fuel degradation.