Draining Mower Gas Before Winter: Siphon, Run Dry or Stabilize
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The short answer
The easiest safe method: add fuel stabilizer, run the engine 5 minutes, then either store it full or siphon the tank into an approved can and run the engine until it stalls. Never tip a mower on its side to pour gas out — fuel and oil end up where they shouldn't.
Hand Siphon Fuel Pump
Safely empties the tank into a can.
Untreated gas goes stale in about a month and leaves varnish in the carburetor, the most common reason mowers won't start in spring. You either treat it or remove it.
Option 1: Stabilize and store
- 1Fill the tank most of the way with fresh gas.
- 2Add stabilizer at the label rate.
- 3Run the engine 5 minutes so treated fuel reaches the carburetor.
Option 2: Siphon, then run dry
- 1Work outdoors with the engine cold.
- 2Use a hand siphon pump into an approved gas can — never by mouth.
- 3Start the mower and let it run until it stalls to clear the carburetor bowl.
Option 3: Drain the carburetor bowl
Many mowers have a drain screw on the bottom of the carburetor bowl. With the fuel valve closed, loosen it over a small container. Retighten snug — don't overtighten.
Frequently Asked Questions
- Should I leave gas in my mower over winter?
- Only if it's treated with stabilizer and run through the engine. Otherwise drain it.
- Can I tip my mower to drain gas?
- Not recommended. Fuel can leak and oil can flood the air filter. Use a siphon.
- Is ethanol-free gas better for storage?
- Yes. Canned ethanol-free fuel stores for years and avoids most carburetor varnish.
The Gear We’d Buy
Everything referenced in this guide, in one place.
Hand Siphon Fuel Pump
Top pickSafely empties the tank into a can.
Typically $10 - $20
STA-BIL Fuel Stabilizer
Keeps gas fresh in storage.
Typically $10 - $15
TruFuel 4-Cycle Fuel
Ethanol-free fuel that stores for years.
Typically $20 - $30
Lawn Tool Hub is reader-supported. We earn a commission from qualifying purchases made through links on this page, at no extra cost to you. Learn more.
Key Takeaways
- Stale gas is the top spring no-start cause.
- Stabilize and run, or siphon and run dry.
- Never tip the mower to drain fuel.
Fix this next
- Winterizing Hoses and Outdoor Faucets Before the First Freeze
Drain and store garden hoses, protect outdoor spigots from freezing, and choose the right hose reel — before the first hard freeze.
- How to Keep Mice Out of a Lawn Equipment Shed
Keep mice from nesting in mower engines and chewing wires by sealing shed gaps, removing food and setting traps in the right places.
Reviewed by
The Lawn Tool Hub Test Bench
We buy, borrow and break lawn tools on our own yards — clay in the back, sand-cut Bermuda in the front — and write down what actually changed the result.
Keep reading
Winterizing Hoses and Outdoor Faucets Before the First Freeze
Drain and store garden hoses, protect outdoor spigots from freezing, and choose the right hose reel — before the first hard freeze.
How to Keep Mice Out of a Lawn Equipment Shed
Keep mice from nesting in mower engines and chewing wires by sealing shed gaps, removing food and setting traps in the right places.
How to Winterize Lawn Equipment for Storage
Gas mowers, edgers, trimmers and battery tools all need proper winter storage. We cover fuel, oil, batteries and blades so everything starts in spring.
Top pick
Hand Siphon Fuel Pump