You’ve rolled your lawn mower out of the shed, ready to tackle that first overgrown lawn of the season. You pull the starter cord with confidence, but instead of a satisfying roar, you’re met with silence, a sputter, or a disappointing chug. It’s a frustratingly common springtime ritual for many homeowners. After months of sitting idle, small engines can be stubborn, but the problem is almost always fixable with a few simple checks.
Before you resign yourself to an expensive trip to the repair shop, take a deep breath. The issue of a lawn mower will not start after winter storage is typically caused by just a handful of culprits related to fuel, air, or spark. With a little patience and some basic troubleshooting, you can likely get your machine running smoothly again in no time.
Why Your Lawn Mower Will Not Start After Winter Storage
The most common villain in this seasonal drama is old gasoline. Modern ethanol-blended fuel begins to break down in as little as 30 days, leaving behind a sticky, gummy residue that clogs the tiny passages in your carburetor. This gunk prevents fuel from reaching the engine, effectively starving it. If you didn’t add a fuel stabilizer before storing your mower, this is the first place to look.
Your Step-by-Step Spring Start-Up Checklist
Start with the simplest solutions first. This systematic approach will help you diagnose the problem without getting overwhelmed.
Check the Basics: Fuel, Oil, and the On/Off Switch
It sounds silly, but first, ensure there is fresh fuel in the tank and that the oil level is correct. Double-check that the mower’s engine stop lever or on/off switch is in the “run” position. Sometimes the simplest oversights are the easiest to fix.
Inspect and Replace the Spark Plug
The spark plug is a common failure point. Remove it using a spark plug socket. If the tip is black with carbon, corroded, or cracked, it needs to be replaced. This is an inexpensive part that makes a world of difference. Before installing the new one, ensure the gap is set correctly according to your mower’s manual.
Address the Fuel System
If the spark plug looks good, old fuel is your likely culprit. Carefully drain any old gasoline from the tank into an approved container. For a more thorough cleaning, you can also drain the carburetor bowl if your mower has one. Fill the tank with fresh, high-octane gasoline. For a severely clogged carburetor, you may need to use a carburetor cleaner spray, but often fresh fuel is enough to clear minor blockages.
Don’t Forget the Air Filter
A dirty air filter can restrict the airflow the engine needs to run. Remove the air filter cover and take out the filter. If it’s a paper filter, hold it up to the light. If you can’t see light through it, it needs to be replaced. If it’s a foam filter, you can wash it in warm, soapy water, rinse it thoroughly, and let it dry completely before adding a few drops of fresh engine oil and reinstalling it.
Preventing the Problem Next Year
To avoid this hassle next spring, prepare your mower for storage properly. Either run the engine until the carburetor is completely out of fuel, or add a fuel stabilizer to a full tank of gas and run the mower for a few minutes to circulate the treated fuel through the system. This simple step is the best insurance against a no-start spring.
By methodically checking the fuel, spark plug, and air filter, you’ve addressed over 90% of the reasons a mower refuses to start after its long winter nap. With these straightforward steps, you can save time and money, and get back to enjoying a beautifully manicured lawn.