How To Remove Gas From Lawn Mower

Knowing how to remove gas from lawn mower is an essential skill for any homeowner. Draining gasoline from a lawn mower prevents fuel system damage during long periods of inactivity, like winter storage. Old fuel can break down, forming gums and varnishes that clog the carburetor and fuel lines. This simple maintenance task can save you from costly repairs and frustrating starting problems next season.

This guide provides clear, step-by-step instructions for safely draining fuel from your mower. We’ll cover the tools you need, different methods for various mower types, and what to do with the old gasoline. Proper fuel management is key to keeping your equipment running smoothly for years.

Before you begin, it’s crucial to prioritize safety and gather the right materials. Working with gasoline requires caution. Always perform this task in a well-ventilated area, preferably outdoors, away from any open flames, sparks, or heat sources. Do not smoke during the process.

You will need a few basic items. Having them ready before you start makes the job quicker and cleaner.

A fuel-safe container: Use an approved gasoline can to hold the drained fuel. Never use makeshift containers like milk jugs or glass bottles.
A length of clear plastic tubing: About 3 feet of 1/4-inch or 5/16-inch tubing works well for siphoning.
A funnel: To help pour any remaining fuel or add fresh gas later without spills.
Safety glasses and gloves: Protect your eyes and skin from gasoline splashes.
A set of wrenches or pliers: You may need these to disconnect a fuel line or remove the carburetor bowl.
Clean rags: For wiping up any drips or spills immediately.

Once your workspace is prepared and your tools are assembled, you can choose the best method for your specific mower. The three primary techniques are siphoning, using the fuel line disconnect, and draining the carburetor bowl.

Method 1: Siphoning The Gasoline

Siphoning is the most common and least invasive method. It works well for most walk-behind mowers and riding mowers where you can easily access the fuel tank. The goal is to use tubing to draw the fuel out by gravity.

Follow these numbered steps for safe siphoning. Never start a siphon by sucking on the tube with your mouth, as ingesting gasoline is extremely dangerous.

Ensure the mower is on a level surface and the engine is completely cool.
Place your empty gas can on the ground, lower than the mower’s fuel tank.
Insert one end of the clean tubing deep into the mower’s gas tank.
For the other end, you have two safe options. You can use a manual siphon pump attached to the tube. Alternatively, you can cover the tube’s end with a rag, quickly blow a short burst of air into the tank to start the flow, then immediately direct that end into your gas can before fuel exits.
Allow the tank to drain completely into the container. You may need to tilt the mower slightly to get the last bit of fuel, but be cautious not to spill oil into the carburetor if you tip it too far.
Once the fuel stops flowing, remove the tubing and securely seal the gas can.

Method 2: Disconnecting The Fuel Line

For mowers with a fuel shut-off valve or an accessible fuel line, this method is very effective. It involves letting the fuel drain directly from the line that runs from the tank to the carburetor. Consult your owner’s manual to locate these components.

Here is the process for disconnecting the fuel line. This method often results in a cleaner, more complete drain.

Locate the fuel line. It is typically a small rubber or plastic hose connecting the gas tank to the carburetor.
Place your gas can underneath the connection point at the carburetor.
Using pliers if necessary, gently clamp the fuel line to prevent immediate flow. Then, carefully disconnect the line from the carburetor nipple.
Direct the open end of the fuel line into your gas can and release the clamp. The gasoline should begin to flow out steadily.
If the flow is slow, you may need to open the gas tank cap to allow air in, which replaces the volume of the draining fuel. This relieves the vacuum that can sometimes form.
After the tank is empty, reconnect the fuel line securely to the carburetor. A loose connection will cause leaks when you add new fuel.

Dealing With A Fuel Shut-Off Valve

Some mowers, particularly older models and riding mowers, have a small valve on the fuel line. This valve is designed to stop fuel flow for maintenance. To use it, simply turn the valve to the “off” position before disconnecting the line at the carburetor. Then, turn it back to “on” to allow the gas to drain. This gives you better control over the flow.

Method 3: Draining The Carburetor Bowl

Even after draining the main tank, a small amount of fuel remains in the carburetor’s float bowl. This old fuel is a prime culprit for starting issues. Draining it ensures your entire system is clean. This step is highly recommended for long-term storage.

Follow these instructions to empty the carburetor bowl. The process varies slightly between carburetor types.

Locate the carburetor. It is usually a metal or plastic component bolted to the side of the engine, with the air filter attached to it.
Look for a small screw or nut at the very bottom of the carburetor bowl. This is the drain screw.
Position your gas can or a small container underneath this screw. A cup or jar works well here.
Using the correct screwdriver or wrench, slowly turn the drain screw counterclockwise. Be prepared for a small stream of gasoline to trickle out.
Let the bowl drain completely. You may need to gently tip the mower to ensure all fuel is removed.
Once drained, carefully retighten the drain screw. Do not overtighten, as you could strip the threads.

After completing any of these methods, it’s a good practice to run the engine until it stalls. This burns off any residual fuel in the carburetor’s internal passages. Simply restart the mower and let it run. When the carburetor is empty, the engine will stop on its own.

What To Do With The Old Gasoline

You must dispose of the old gasoline properly. Never pour it down a drain, into the soil, or into the regular trash. Gasoline is a hazardous material that contaminates water and soil.

Here are your responsible options for handling used lawn mower fuel.

Reuse it: If the gasoline is relatively fresh (less than 30 days old) and uncontaminated, you can mix it with fresh gas in your car’s tank. Dilute it by adding no more than one gallon of old gas to a nearly full tank of fresh fuel. Your car’s fuel system can handle this small amount.
Recycle it: The best option is to take it to a hazardous waste disposal facility or a recycling center that accepts gasoline. Many communities hold periodic collection events for household hazardous waste. Check with your local government or auto parts stores, as some accept old fuel for a fee.
Use a fuel stabilizer: If you know the gas is going to sit for more than a month, add a fuel stabilizer like STA-BIL when you first fill the can. This extends its life significantly, allowing you to use it in your mower later without issue.

Storing gasoline long-term requires an approved container in a cool, dry place away from living spaces. Properly labeled containers prevent accidents and confusion.

Preventative Tips For Fuel System Health

Removing gas is often a reactive step. Adopting proactive habits can minimize the need for draining and keep your mower in top condition. These simple tips will extend the life of your engine’s fuel system.

First, consider using a fuel stabilizer year-round. Adding stabilizer to every can of fresh gas before you pour it into the mower keeps the fuel from degrading for up to 24 months. This is especially helpful if you don’t use your mower frequently.

Second, try to run your mower dry at the end of the mowing season. If you know you won’t be using it for several months, simply let it run until it stops. This empties the carburetor, which is the most suseptible part to varnish buildup.

Finally, perform regular maintenance. Replace the air filter annually and use fresh, ethanol-free gasoline if it’s available in your area. Ethanol attracts moisture, which leads to phase separation and corrosion inside the fuel system. These small steps make a big difference.

Common Mistakes To Avoid

Even with good intentions, a few common errors can cause problems. Being aware of these pitfalls helps you complete the job safely and effectively.

Storing the mower with a full tank without stabilizer: This seems logical but leads to the most damage. The large volume of untreated fuel will break down over months.
Using improper containers: Gasoline can degrade plastic not meant for fuel, causing leaks and dangerous fumes. Always use UL-approved or DOT-certified gas cans.
Forgetting to drain the carburetor bowl: This small reservoir of fuel is often overlooked, leading to the very clogs you’re trying to prevent.
Ignoring safety gear: Gasoline vapors are harmful, and skin contact can cause irritation. Always wear gloves and safety glasses, even for a quick job.
Tipping the mower the wrong way: If you need to tilt it to drain the last bit of fuel, always tip it so the spark plug side is facing up. Tilting it the other way can allow oil to flood the cylinder and cause hydraulic lock.

FAQ: Frequently Asked Questions

Here are answers to some common questions about removing gas from lawn mowers.

How Often Should I Remove Gas From My Lawn Mower?

You should drain the gas if you plan to store the mower for more than 30 days without using it. For seasonal storage over winter, draining is highly recommended. For shorter breaks, using a fuel stabilizer is a good alternative.

Can I Leave Gas In My Lawn Mower Over Winter?

It is not advisable to leave untreated gasoline in your mower over winter. The fuel will likely deteriorate and cause starting problems in the spring. If you choose not to drain it, you must add a high-quality fuel stabilizer to a full tank and run the engine for 5 minutes to circulate it before storage.

What Is The Easiest Way To Get Gas Out Of A Lawn Mower?

The easiest method for most homeowners is siphoning with a manual pump. It requires minimal tools and no disassembly of engine parts. For mowers with a handy fuel line disconnect, that method is also very straightforward and less messy than siphoning sometimes.

Why Is My Lawn Mower Hard To Start After Storage?

This is almost always due to old, degraded gasoline clogging the carburetor jets and passages. The gummy residue prevents the proper mix of air and fuel from reaching the engine. Draining the fuel system before storage or using a stabilizer prevents this common issue.

Is It Better To Drain Gas Or Use A Stabilizer?

For long-term storage (over 4-6 months), draining the fuel system is the most thorough and reliable method. For shorter periods or if you prefer not to drain, a stabilizer is an excellent preventative measure. For ultimate protection, some experts recommend both: adding stabilizer to fresh gas and then running the engine dry.