Spring is here, and your lawn is calling. If you’re wondering how to start a lawn mower after the winter, you’re not alone. Starting a mower after months of winter storage often requires checking a few key systems first. Gas goes stale, oil gets dirty, and parts can seize up. This guide will walk you through the safe, step-by-step process to get your machine running smoothly for the first cut of the season.
How To Start A Lawn Mower After The Winter
Before you even think about pulling the starter cord, there are essential pre-start checks. Rushing this process can lead to frustration or even damage your mower. A systematic approach saves time and ensures your safety. Follow these steps in order for the best results.
Gather Your Tools And Supplies
Having everything you need on hand makes the job quicker. You likely have most of these items in your garage already.
- Fresh gasoline (with the correct octane rating for your mower)
- New engine oil (check your manual for the specific type and weight)
- A new spark plug
- A socket wrench or spark plug socket
- A funnel
- An oil drain pan
- A wire brush or old toothbrush
- A pair of gloves and safety glasses
Safety First: Preparing Your Workspace
Always work in a well-ventilated area, like a driveway or open garage. Make sure the mower is on a flat, level surface. Disconnect the spark plug wire before you begin any work. This is the most critical safety step—it prevents the engine from accidentally starting while your hands are near the blade.
Why Disconnecting The Spark Plug Is Non-Negotiable
Even with the ignition switch off, a simple pull of the cord could engage the blade. By disconnecting the wire from the spark plug, you completely eliminate the risk of an unexpected start. It’s a five-second task that protects your fingers.
Step 1: Remove Old Fuel And Clean The System
Old gasoline is the number one reason lawn mowers fail to start in spring. Over winter, gas deteriorates, leaving behind gummy varnish and clogging the carburetor.
- Locate the fuel line or fuel tank shut-off valve if your mower has one. Turn it to the “off” position.
- Place your oil drain pan beneath the mower’s fuel tank.
- Use a siphon pump or carefully tilt the mower to drain all the old gasoline into the pan. Dispose of this fuel properly at a recycling center—do not pour it on the ground or down a drain.
- Once empty, add a small amount of fresh fuel to the tank. Swirl it around and drain it again to help flush out any remaining residue.
Step 2: Change The Engine Oil
Oil breaks down over time, even when the engine isn’t running. Starting with clean oil reduces wear on engine components.
- Run the engine for a minute or two if there’s still old fuel in it to warm the oil (if you can’t start it, skip this). Warm oil drains more completely.
- Place your drain pan under the oil drain plug, usually located on the underside of the mower deck.
- Remove the drain plug and let the old oil flow out completely. Replace the plug securely.
- Find the oil fill cap on top of the engine. Use your funnel to add the new, manufacturer-recommended oil. Check the dipstick to ensure you fill it to the proper level—do not overfill.
Step 3: Inspect And Replace The Spark Plug
A fouled or corroded spark plug won’t create the spark needed for combustion. This is a cheap and simple fix.
- Pull off the rubber spark plug wire boot.
- Use your socket wrench to carefully unscrew the old spark plug.
- Inspect the electrode. If it’s black, oily, or has heavy corrosion, it needs replacing. Even if it looks okay, replacing it annually is good practice.
- Check the gap on your new spark plug with a gap tool, adjusting it to the specification in your manual (a common gap is 0.030 inches).
- Thread the new plug in by hand to avoid cross-threading, then tighten it with the wrench. Reconnect the rubber boot firmly.
Step 4: Check And Clean The Air Filter
A clogged air filter starves the engine of air, making it run poorly or not at all. There are two main types: paper or foam.
- For a paper filter: Tap it gently on a hard surface to dislodge loose dirt. If it’s very dirty, replace it. Do not wash a paper filter.
- For a foam filter: Remove it and wash it in warm, soapy water. Rinse it thoroughly and let it dry completely. Once dry, apply a few drops of clean engine oil to it, then squeeze it to distribute the oil evenly before reinstalling.
Step 5: Inspect The Mower Deck And Blade
While the mower is safely disabled, take a moment to look underneath. Clear any caked-on grass clippings from the deck with a brush or scraper. This buildup restricts airflow and cutting efficiency. Carefully check the blade for nicks, bends, or excessive dullness. A sharp blade makes for a healthier lawn. If it’s damaged, replace it or have it professionally sharpened.
Step 6: The Moment Of Truth: Starting The Engine
Now that the maintenance is complete, you can attempt to start the mower. Reconnect the spark plug wire first.
- If your mower has a primer bulb, press it 3-5 times to draw fuel into the carburetor.
- If it has a choke, move the lever to the “Choke” or “Start” position.
- Set the throttle control to the fast or start setting.
- For a push mower, firmly grip the handle and pull the starter cord smoothly and briskly. Do not yank it or let it snap back violently.
- For a riding mower, ensure the parking brake is set, the blade engagement is off, and you are in neutral. Turn the key to start.
- Once the engine starts, move the choke lever to the “Run” position gradually as the engine warms.
Troubleshooting Common Starting Problems
If the engine doesn’t start, don’t panic. Work through this checklist.
Engine Won’t Turn Over Or Pull Is Very Hard
- Check that the spark plug wire is firmly connected.
- The engine could be hydro-locked from excess fuel or oil. Remove the spark plug and pull the cord a few times to clear the cylinder. Reinstall the plug.
- Mechanical seizure from lack of oil is possible but less common if you changed it.
Engine Turns Over But Won’t Start
- Confirm you have fresh, clean fuel in the tank.
- Double-check that the fuel valve (if equipped) is in the “On” position.
- Ensure the air filter is clean and properly installed.
- Verify the spark plug is gapped correctly and installed tightly.
Engine Starts Then Sputters And Dies
This usually points to a fuel delivery issue. The carburetor’s small jets may still be clogged with old fuel residue. You may need to use a carburetor cleaner additive in your fresh gas, or in more stubborn cases, remove and clean the carburetor manually.
Preparing For The Mowing Season
After you’ve successfully started the mower, let it run for a few minutes to circulate the new oil and reach operating temperature. Listen for any unusual noises and check for leaks. Give the wheels and height adjustment levers a quick check to ensure they’re working properly. You’re now ready for your first mow. Remember to only cut off one-third of the grass blade height at a time for the healthiest lawn.
FAQ: Starting Your Lawn Mower After Winter
What Is The Best Way To Store A Lawn Mower For Winter?
The best practice is to add a fuel stabilizer to a full tank of gas and run the engine for five minutes before storage. Then, change the oil, clean the deck, and remove the battery (for riding mowers) for indoor charging. This prevents most spring starting issues.
Can I Use The Same Gas From Last Year In My Mower?
No, you should not use old gasoline. Gasoline begins to degrade in as little as 30 days, losing volatility and forming gums that clog the fuel system. Always drain old fuel or use a stabilizer if you plan to store fuel over winter.
How Often Should I Change The Spark Plug On My Mower?
For optimal performance, change the spark plug at least once per mowing season. Doing it as part of your spring startup routine is a reliable habit. A new plug ensures a strong spark for easier starting.
Why Does My Mower Smoke When I First Start It After Winter?
A little blue or white smoke on initial startup is often normal. It can be caused by a small amount of oil that seeped into the cylinder during storage. It should clear up after a minute of running. Persistent smoke, especially black smoke, could indicate over-oiling or a carburetor running too rich.
Do I Need To Charge The Battery On My Riding Mower Before Spring?
Yes, you absolutely should. Cold temperatures can drain a battery over winter. Connect a smart battery charger to maintain it during storage or give it a full charge before your first startup attempt. A weak battery is a common reason riding mowers won’t crank.