Can you clean a lawn mower fuel tank? Yes, you absolutely can and should clean your lawn mower’s fuel tank if it’s dirty or if you plan to store the mower for an extended period. A clean fuel tank ensures your mower runs smoothly and prevents potential damage. This guide will walk you through the process step-by-step, focusing on safety and effectiveness.
Regularly cleaning your lawn mower’s fuel tank is a crucial part of proper mower maintenance. Over time, fuel can degrade, leaving behind gummy deposits, rust, and water, which can clog fuel lines and the carburetor. This can lead to poor engine performance, difficulty starting, or even complete failure. Following these steps will help you keep your lawn mower in top condition.
Why Cleaning the Fuel Tank is Important
A clean fuel system is vital for a well-functioning lawn mower. Here’s why tackling a dirty fuel tank is essential:
- Prevents Clogs: Old fuel can break down, forming varnish and gum. These sticky residues can block fuel lines and the tiny jets within the carburetor, starving the engine of fuel.
- Eliminates Water Contamination: Water can get into fuel tanks through condensation or from contaminated fuel. Water doesn’t burn and can cause corrosion within the tank and fuel system.
- Stops Rust: If your fuel tank is metal, moisture can lead to rust. Rust particles are abrasive and can damage engine components.
- Ensures Proper Fuel Flow: A clean tank allows for consistent fuel delivery to the engine, ensuring optimal power and performance.
- Extends Engine Life: By preventing fuel system issues, you reduce wear and tear on the engine, contributing to a longer lifespan for your lawn mower.
Preparing for the Task
Before you begin, gather the necessary tools and safety gear. This will make the process smoother and safer.
Essential Tools and Supplies
- Safety Glasses: To protect your eyes from fuel splashes or debris.
- Gloves: Chemical-resistant gloves (like nitrile) to protect your skin from fuel and cleaning agents.
- Siphon Pump or Fuel Transfer Pump: To safely remove old fuel.
- Clean, Approved Fuel Container: To store the old fuel and any draining fluids. This container should be specifically designed for gasoline.
- Funnel: For safely pouring in fresh fuel or cleaning solutions.
- Clean Rags or Paper Towels: For wiping and cleaning.
- Wire Brush or Scrubber: For scrubbing stubborn deposits. A long-handled brush is ideal for reaching the bottom of the tank.
- Small Screwdriver or Flathead Tool: To help dislodge any stubborn debris.
- Mild Detergent: For washing the outside of the tank if needed.
- Compressed Air: Optional, but helpful for drying the tank.
- New Fuel Filter: It’s a good idea to replace this while you’re at it.
- Fresh Fuel: For refilling after cleaning.
- Fuel Stabilizer: If you plan to store the mower.
Safety Precautions First
Working with gasoline requires strict adherence to safety. Never perform this task in an enclosed space or near open flames, sparks, or smoking.
- Ventilation: Always work in a well-ventilated area, preferably outdoors. Gasoline fumes are flammable and harmful to inhale.
- No Smoking: Absolutely no smoking or open flames nearby.
- Static Electricity: Be mindful of static electricity. Ground yourself by touching a metal object before handling fuel or containers.
- Proper Disposal: Dispose of old fuel responsibly. Check with your local authorities for hazardous waste disposal guidelines. Never pour it down a drain or onto the ground.
- Disconnect Spark Plug: Before starting any work on the mower, always disconnect the spark plug wire. This prevents accidental engine starting.
Step-by-Step Guide to Cleaning the Fuel Tank
The process of cleaning a lawn mower fuel tank involves draining the old fuel, physically cleaning the inside, and preparing it for fresh fuel.
Step 1: Empty the Lawn Mower Tank
The first and most critical step is to empty lawn mower tank of all its contents.
- Locate the Fuel Shut-Off Valve: Most lawn mowers have a fuel shut-off valve. Turn this valve to the “OFF” position. If your mower doesn’t have one, you’ll need to disconnect the fuel line from the carburetor (usually a small rubber hose connected to a metal fitting). Be prepared for some fuel to spill.
- Use a Siphon Pump: Insert one end of the siphon pump into the fuel tank and the other end into your approved fuel container. Pump the handle to start the flow of fuel.
- Alternatively, Disconnect Fuel Line: If you can’t siphon, carefully disconnect the fuel line from the carburetor. Place the end of the fuel line into your approved fuel container, and gravity should help drain the tank, especially if the tank is positioned higher than the container. You might need to tilt the mower slightly to get all the fuel out, but be careful not to spill oil into the wrong places.
- Remove Fuel from Mower: Ensure you remove fuel from mower completely. What remains can be very small amounts, but these are often the most problematic due to settling sediment.
Step 2: Inspect the Fuel Tank
Once the tank is empty, take a moment to inspect it.
- Visual Check: Shine a light into the tank opening. Look for any signs of rust, debris, water droplets, or gummy deposits on the inside walls.
- Fuel Cap: Check the fuel cap for any damage or debris. Ensure the vent in the cap is clear. A clogged vent can cause fuel delivery problems.
Step 3: Clean the Inside of the Tank
Now it’s time to clean gas tank mower internals. The method depends on the severity of the contamination.
For Light Contamination (Dust, Minor Debris)
- Rinse with Fresh Fuel: Pour a small amount of fresh gasoline (about a pint) into the tank. Swirl it around vigorously to pick up any loose debris.
- Siphon Again: Use your siphon pump to remove this rinse fuel into your approved container.
- Wipe: Use clean rags or paper towels to wipe around the tank opening and the visible parts of the tank interior.
For Moderate to Heavy Contamination (Gummy Deposits, Water, Rust)
This often requires a more thorough cleaning.
- Drain All Fuel: Ensure the tank is completely empty as described in Step 1.
- Add Cleaning Agent: You have a few options for cleaning agents:
- Fresh Gasoline: Pour about a quart of fresh gasoline into the tank. Add a handful of small nuts or ball bearings (ensure they are rust-free). Close the tank cap securely and shake the mower vigorously. The gasoline and the abrasive action of the nuts will help dislodge deposits.
- Approved Fuel Tank Cleaner: Follow the manufacturer’s instructions for a specialized fuel tank cleaner. These are often effective for breaking down varnish and gum.
- Water and Mild Soap (for non-metal tanks only): If your tank is plastic, you can use warm water and a small amount of mild soap. Scrub with a brush, then rinse thoroughly with clean water. Crucially, you must ensure the tank is completely dry if you use water.
- Scrub: Use a long-handled brush or a flexible scrubber to scrub the inside of the tank. Pay attention to the bottom and any corners where sediment tends to accumulate. A bent piece of wire with a rag wrapped around it can also help reach difficult spots.
- Siphon and Rinse: After scrubbing, siphon out the cleaning solution. You may need to repeat the cleaning process and siphoning steps multiple times until the fluid you remove is clean.
- Final Rinse (Optional but Recommended): For a final rinse, you can use a small amount of fresh gasoline again to remove any lingering cleaning residue or fine particles. Siphon this out immediately.
Important Note on Materials: If your fuel tank is made of metal, avoid using water and soap unless you are absolutely certain you can dry it completely and immediately to prevent rust. For metal tanks, gasoline or a dedicated fuel tank cleaner is preferred.
Step 4: Dry the Fuel Tank
This is a critical step, especially if you used any water-based cleaner or if there’s any suspicion of moisture.
- Air Dry: Leave the fuel cap off and let the tank air dry thoroughly. Placing it in a warm, sunny spot can speed up the process.
- Compressed Air: If you have access to compressed air, you can blow air into the tank to help evaporate any remaining moisture. Direct the air carefully to avoid creating static.
- Wipe with Dry Rags: Use clean, dry rags to wipe any accessible surfaces inside the tank.
Step 5: Inspect and Replace Fuel Filter
While the tank is accessible, it’s a good time to inspect and potentially replace the fuel filter.
- Locate: The fuel filter is usually located in the fuel line between the tank and the carburetor.
- Inspect: Look for any signs of discoloration, debris, or blockage in the filter.
- Replace: If it looks dirty or you’re unsure of its condition, replace it with a new one. Make sure to note the direction of fuel flow indicated on the filter.
Step 6: Refill the Tank
Once the tank is clean and completely dry, it’s time to add fresh fuel.
- Use Fresh Fuel: Fill the tank with clean, fresh gasoline. Using fresh fuel lawn mower is essential for optimal performance. If you’ve been using ethanol-free gasoline, stick with it if possible. Ethanol can absorb moisture and cause corrosion over time.
- Add Fuel Stabilizer: If you plan to store lawn mower fuel or the mower itself for more than a month, add a fuel stabilizer mower to the fresh fuel. Follow the product’s instructions for the correct ratio. A lawn mower gas treatment can prevent fuel degradation during storage.
- Use a Funnel: Always use a funnel to prevent spills when refilling.
Dealing with Specific Issues
Sometimes, your fuel tank might have particular problems that need addressing.
Rust in Metal Fuel Tanks
Rust is a common problem in older metal fuel tanks.
- Remove Loose Rust: After draining, use a rust remover designed for fuel tanks. Follow the product’s instructions carefully. You might need to let it sit in the tank for a period.
- Scrubbing: Use a rust-removing solvent and a brush or chain to help knock loose rust particles.
- Rinse and Dry Thoroughly: Rinse with fresh gasoline and dry completely.
- Sealing (Optional): For tanks with significant rust or minor pinholes, consider using a fuel tank sealer. These products create a protective coating inside the tank. Clean the tank meticulously before applying any sealer, and follow the manufacturer’s instructions precisely.
Water Contamination
Water in the fuel tank is problematic.
- Drain Completely: Ensure all gasoline and any water is thoroughly drained.
- Repeat Cleaning: If you suspect a significant amount of water has been in the tank, repeat the cleaning process using fresh gasoline. Siphon multiple times.
- Dry Thoroughly: The tank must be completely dry to prevent further condensation and rust.
Storing Your Lawn Mower Properly
Proper storage is key to preventing future fuel tank issues.
Short-Term Storage (Less than 30 days)
For storage periods of less than a month, you can generally leave fuel in the tank. However, adding a fuel stabilizer is still a good idea to maintain fuel quality.
Long-Term Storage (30 days or more)
For longer storage, you have two main options:
- Treat the Fuel: Fill the tank with fresh gasoline and add a quality fuel stabilizer. Run the engine for a few minutes to allow the stabilized fuel to circulate through the carburetor. This is often the preferred method.
- Drain the Tank Completely: If you prefer not to use fuel stabilizers or if you want to be extra cautious, you can drain the fuel tank completely. Store the mower in a dry, well-ventilated area.
Storing Lawn Mower Fuel: If you drain fuel from the mower, store it in an approved, sealed container in a cool, dry place away from ignition sources. Never store gasoline for extended periods without a stabilizer, as it will degrade and can cause engine problems.
Advanced Cleaning and Carburetor Care
Sometimes, a dirty fuel tank indicates that the carburetor may also be affected.
Carburetor Cleaner Mower
If your mower is running rough or the fuel tank was heavily contaminated, it’s wise to consider cleaning the carburetor.
- Removal: You may need to remove the carburetor from the mower for a thorough cleaning. Consult your mower’s manual for specific instructions.
- Cleaning: Use a specialized carburetor cleaner mower spray. Spray the cleaner into the jets, orifices, and passages of the carburetor. Allow it to soak if the cleaner instructions recommend it.
- Reassembly: Reassemble the carburetor and reinstall it on the mower.
Fuel System Cleaning
Some products are designed to clean the entire fuel system, from the tank to the carburetor. These can be added to the fuel tank and run through the engine. Always follow product instructions carefully.
Frequently Asked Questions (FAQ)
Q1: How often should I clean my lawn mower fuel tank?
You don’t need to clean it every time you use it. However, it’s a good practice to clean it annually before winter storage, or if you notice symptoms of fuel system problems like poor starting or rough running. If you use your mower regularly, ensure you use fresh fuel lawn mower and consider a fuel stabilizer mower to prevent issues.
Q2: What’s the best way to remove old fuel?
The safest and most effective way is to use a siphon pump or a dedicated fuel transfer pump. Always remove fuel from mower into an approved container.
Q3: Can I use water to clean my lawn mower fuel tank?
Yes, but only if your fuel tank is made of plastic. For metal tanks, water can cause rust. If you use water on a plastic tank, ensure it is completely dry before refilling with fuel.
Q4: What kind of fuel should I use in my lawn mower?
Use fresh, unleaded gasoline with an octane rating recommended by your mower’s manufacturer (usually 87 octane). Ethanol-free gasoline is preferable if available, as ethanol can absorb moisture and cause corrosion.
Q5: My fuel tank is rusty. What can I do?
For light rust, you can try a rust remover designed for fuel tanks or use a mixture of fresh gasoline and small metal parts (like nuts or ball bearings) to scrub the inside. For severe rust, consider a fuel tank sealer or replacing the tank.
Q6: How do I store gasoline for my lawn mower?
Store gasoline in an approved, sealed gasoline container in a cool, dry, well-ventilated area away from heat sources or open flames. Always add a quality fuel stabilizer if you plan to store lawn mower fuel for more than 30 days.
By following these guidelines, you can ensure your lawn mower’s fuel tank is clean, protected, and ready to provide reliable service for years to come. Proper mower maintenance gas handling and system cleaning are key to a healthy engine.