Realizing you forgot to winterize your lawn mower as spring arrives leads to a few important checks. That moment of panic is common, but don’t worry. This guide will walk you through exactly what to do. You can still get your mower running smoothly for the season ahead.
First, take a deep breath. Many people forget this crucial fall task. The goal now is damage assessment and corrective action. We will cover checking the fuel system, engine, and all critical components. You’ll learn step-by-step how to revive your mower.
Forgot To Winterize Lawn Mower
This section is your starting point. The keyword is your situation, and this is your action plan. Winterizing protects a mower from fuel degradation, moisture, and corrosion. Skipping it can lead to starting problems, poor performance, or permanent damage. Your first job is to not try starting the engine immediately. That could cause more harm if old fuel is gummed up inside.
Immediate Steps To Take Right Now
Before you touch the starter cord or turn the key, follow these steps. They prevent you from compounding any existing problems. Safety is always the first priority.
- Move the mower to a flat, well-ventilated area like a garage or driveway.
- Disconnect the spark plug wire. This ensures the engine cannot accidentally start while you are working.
- Take a moment for a visual inspection. Look for obvious signs of damage, pests, or nesting materials around the engine deck and wheels.
Checking For Obvious Damage
Look over the mower carefully. Check the blade for excessive rust or chips. Look at the wheels and cables. See if there are any fluid leaks underneath. Make a note of anything that looks broken or severely corroded. This visual check gives you a baseline before diving into the engine systems.
Dealing With Old Fuel In The System
This is the most common and critical issue. Gasoline left in the tank and carburetor over winter breaks down. It forms varnish and gum that clogs small passages. This is the primary reason a mower won’t start after storage.
How To Drain The Fuel Tank
You need to remove all the old fuel. For a plastic tank, you can often siphon it out using a hand pump. Place the old fuel into an approved gasoline container for disposal. Do not pour it on the ground or down a drain. Many service stations or hazardous waste facilities accept old gas. If the tank is metal and you see rust inside, that will need special attention after draining.
Addressing The Carburetor
The carburetor is likely clogged. After draining the tank, you should remove the carburetor bowl. This is usually held on by a single bolt on the bottom. Be prepared for some residual fuel to drip out. Inside, you may find a jelly-like substance. Clean the bowl and the small jet inside with carburetor cleaner and a soft wire. If you are uncomfortable doing this, a can of aerosol carburetor cleaner sprayed into the intake might help, but disassembly is more effective.
Spark Plug Inspection And Replacement
A fouled spark plug is another common culprit. Old fuel and condensation can cause it to fail. Use a spark plug socket wrench to remove the plug. Inspect the electrode end. It should be a light tan or gray color. If it’s black, oily, or has heavy carbon deposits, it needs to be replaced. Even if it looks okay, replacing it is a cheap and good practice after a forgotten winterization. Check your manual for the correct plug type and gap setting.
Step By Step Engine Revival Process
Now that you’ve adressed the fuel and spark, it’s time to systematically bring the engine back to life. Follow these steps in order for the best chance of success.
Step 1: Fresh Fuel And Stabilizer
Once the system is drained and cleaned, add fresh, high-octane gasoline. For small engines, ethanol-free fuel is best as it doesn’t attract moisture. Add a fuel stabilizer to the new gas according to the bottle’s instructions. This will help keep it fresh during the mowing season, especially if you won’t use it all quickly.
Step 2: New Engine Oil And Filter
Engine oil breaks down and can become contaminated with moisture and fuel over time. Even if you changed it last fall, change it again now. Drain the old oil into a pan, replace the drain plug, and refill with the type and weight specified in your manual. If your mower has an oil filter, replace that too. Clean oil is essential for lubrication and preventing engine wear.
Step 3: Air Filter Maintenance
Locate the air filter housing. Remove the 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, replace it. If it’s a foam filter, you can wash it in warm soapy water, rinse thoroughly, let it dry completely, and then apply a few drops of fresh engine oil before reinstalling. A clean air filter ensures proper air flow for combustion.
Step 4: Battery Check For Electric Start Models
If your mower has a battery, it’s probably dead. Remove it and take it to an auto parts store for a load test. They can tell you if it can hold a charge. If it’s salvageable, charge it slowly with a low-amp battery charger. If it’s dead, you’ll need a new one. Ensure the terminals are clean and free of corrosion before connecting the new or charged battery.
Additional Systems To Inspect
With the engine addressed, turn your attention to the rest of the mower. These components affect safety and cut quality.
Sharpening Or Replacing The Mower Blade
A dull or damaged blade tears grass, leaving a brown, ragged cut. It also makes the engine work harder. Carefully tip the mower on its side (with the air filter and carburetor facing up to prevent oil leaks). Use a wrench to remove the blade. Inspect it for deep nicks, cracks, or severe rust. You can sharpen it with a file or grinder, ensuring you balance it afterward. If it’s badly damaged, replacement is safer and more effective.
Checking Drive Systems And Cables
For self-propelled mowers, check the drive system. Engage the drive lever and try to turn the wheels by hand; they should resist. Look at the control cables for the throttle and drive for fraying or stiffness. Lubricate any cable linkage points with a light oil like WD-40 to ensure smooth operation. This step is often overlooked but makes using the mower much easier.
Inspecting Belts And Pulleys
Riding mowers have belts that drive the blades and transmission. Inspect these for cracks, glazing, or fraying. A broken belt will stop your mower dead. Check the pulleys the belts ride on for rust or debris. Spin them by hand to ensure they turn freely. Replace any belt that shows significant wear.
First Startup Attempt And Troubleshooting
You’ve done all the prep work. Now it’s time for the moment of truth. Reconnect the spark plug wire. For a push mower, set the throttle to the start position. For a riding mower, ensure it’s in neutral with the parking brake set.
If The Engine Cranks But Won’t Start
This usually points to a fuel or spark issue. Double-check that you opened the fuel valve if your mower has one. Confirm you have fresh gas. Verify the spark plug wire is firmly attached. You might need to re-clean the carburetor jet more thoroughly. Sometimes, a small piece of debris remains.
If The Engine Starts But Runs Roughly
An uneven sputtering sound means the engine is running but not well. This often indicates a still-partially clogged carburetor or water in the fuel system. Let it run for a few minutes; sometimes fresh fuel can clear minor clogs. If it continues, you may need a professional carburetor cleaning or rebuild kit.
If There Is Unusual Noise Or Vibration
Shut the engine off immediately. Loud knocking, screeching, or excessive vibration signals a serious mechanical problem. It could be a loose blade, damaged engine bearing, or a problem with the drive system. Do not ignore these sounds. Continuing to run the mower could lead to catastrophic failure.
Preventing The Problem Next Year
Now that you’ve gone through this, you won’t want to repeat it. Here is a simple end-of-season checklist to follow next fall. Stick it on your mower’s handle or in your tool box.
- Add fuel stabilizer to a full tank and run the engine for 5 minutes to circulate it.
- Disconnect the spark plug and safely remove the blade for sharpening.
- Change the engine oil while it’s warm from that last run.
- Clean the mower deck thoroughly to remove grass clippings and mud.
- Remove the battery and store it indoors on a wooden block, trickle charging it once over winter.
- Store the mower in a dry, covered place like a shed or garage.
Creating A Seasonal Maintenance Reminder
The best way to remember is to set a calendar reminder on your phone for late October. Pair it with another fall task, like raking leaves or putting away patio furniture. A little prevention saves a lot of springtime frustration and repair costs.
Frequently Asked Questions
What Happens If You Do Not Winterize A Lawn Mower?
If you do not winterize a lawn mower, old fuel will degrade and clog the carburetor and fuel lines. Moisture can cause rust in the tank and on engine components. The battery may sulfate and die. These issues lead to starting failures, poor performance, and potentially expensive repairs in the spring.
Can You Use Old Gas In A Lawn Mower?
You should not use old gas in a lawn mower. Gasoline begins to break down after about 30 days, losing combustibility and forming gums. Using it can clog the fuel system and prevent starting. Always use fresh fuel, preferably ethanol-free, for small engines.
How Do You Start A Lawn Mower That Was Not Winterized?
To start a lawn mower that was not winterized, first drain all old fuel from the tank and carburetor. Add fresh gasoline with stabilizer. Check and likely replace the spark plug. Change the engine oil. After these steps, attempt to start it. If it still doesn’t start, the carburetor likely needs a professional cleaning.
Is It Too Late To Winterize My Lawn Mower In Spring?
Yes, it is too late to winterize your lawn mower in the traditional sense, as winter has passed. However, you can perform the corrective “spring revival” steps outlined in this article. This involves addressing the problems caused by lack of winterization, such as draining old fuel and changing the oil.
Will Seafoam Help A Lawn Mower That Wasn’t Winterized?
Seafoam or similar fuel additives can help clean minor fuel system deposits. For a mower that wasn’t winterized, adding it to fresh fuel may help dissolve light gum and varnish. However, for severe clogs from months-old degraded fuel, physical cleaning or carburetor disassembly is usually necessary for a complete fix.