How To Drain Gas From a Lawn Mower (DIY) | Family Handyman

Less than 30 minutes

Beginner

$20-50

I love a gas-powered mower for effortlessly cutting a large lawn. But I'm mindful of the meticulous maintenance needed to keep them running smoothly. Being lax with lawn mower winterization can cause engine troubles when it's time to trim your spring turf. Learning when and how to drain gas from a lawn mower helps prevent frustrating starter issues.

I spoke with experts from leading lawn mower manufacturers to get their tips on safely siphoning off fuel from gas grass cutters. Follow these to dive into your spring lawn care calendar without delay.

Stale gas is a leading cause of lawn mower performance issues and breakdowns. David Bush is the assistant manager of shows, events and sponsorship at Honda Power Sports & Products Division. He explains most mower gasoline contains ethanol, a moisture-attracting alcohol. "Tiny amounts of water are generally ok, but larger quantities will likely cause corrosion (rust) and could clog the fuel system or carburetor," he says. According to Bush, this can lead to the lawn mower not starting or running roughly, and you could end up with a costly repair bill.

Although timings vary depending on fuel blends, quantities in the tank and temperatures, gas can go bad within a month of leaving the mower idle. When you're putting your lawn mower into storage during the cold season, draining the gas is a key part of the winterization process. Vince Jagodzinski, the corporate grounds manager at Stanley Black & Decker, explains you might also need to drain gas from a lawn mower when transporting it in a vehicle to prevent damaging, flammable spills.

"Anytime you're handling gasoline, a risk is present," Bush says. It's highly flammable, and the vapors are toxic.

To minimize the risk, take the following precautions when draining gas from a lawn mower:

Jagodzinski also recommends referring to the manufacturer's instructions to check for any model-specific safety guidance.

Jagodzinski suggests hiring a professional to drain the gas from your lawn mower when:

Read the manufacturer’s instructions, as there’s often model-specific guidance on how to drain gas from your lawn mower. Jagodzinski also recommends cleaning and clearing a flat workspace and laying out the tools and supplies to help you visualize the process and complete the task safely.

An inexpensive fuel siphon pump is the best tool for emptying the tank. “It offers good control when transferring fuel into a container, helping to prevent spillage,” Bush says.

Don’t tilt the mower to empty it of fuel. It could flood the carburetor, soak the air filter and cause spillages.

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Small amounts of gas can linger in the fuel lines and carburetor (where gas and air blend into a combustible mixture). To remove, reconnect the spark plug, start the engine and let it run until it stalls. “Continue to attempt to restart the engine until it no longer starts,” Carothers says.

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Carothers explains you can’t throw the old gas in your regular trash. “Follow your city’s guidelines for disposing of hazardous waste,” she says. You can find these details on your city’s official website.

It’s possible to run a mower dry rather than draining the gas. While this isn’t an economical or environmentally friendly option if you have a full tank, it’s convenient when there isn’t much gas left during your last fall mow.

Another option is adding a fuel stabilizer. This helps keep your gas from going stale for at least 12 months. Carothers explains it protects your carburetor from corrosion, dissolves fuel system deposits and promotes easy starting after storage.

Robert Maxwell for Family Handyman