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Lawnmower Won’t Start After Winter

Lawnmower Won’t Start After Winter

After the long, cold winter months and as the days become warmer, most people want to use their lawnmowers again. However, getting a lawnmower started after sitting for several months can prove difficult. If your lawnmower doesn’t start after winter, you may wonder why and if that’s normal.

Your lawnmower won’t start after winter, probably because it has a dead battery, stale gas, dirty spark plug, clogged components, or damaged belts. When these happen, you’ll need to clean the lawnmower and replace the defective parts before starting up the equipment again. 

The rest of this article will explain why your lawnmower won’t start after sitting for long and what you can do to get it started. Read on for more details on these and tips on maintaining your lawnmower to help keep it running all season smoothly. 

Lawn Mower Won’t Start After Sitting

You go to start your lawnmower after taking a break during the winter, but it won’t turn over. You try again and again, but no luck. Has this ever happened to you? 

You’re not alone. Typically, a lawnmower that won’t start is common for those owning gas-powered lawn equipment.

So what’s preventing your lawnmower from starting? 

Let’s find out!

Your Lawnmower’s Battery Is Dead

A dead battery is one of the most common reasons a lawnmower won’t start after sitting for too long. The battery in your lawnmower stores energy to power the spark plug, creating the combustion necessary for the equipment to run.

Batteries are susceptible to losing their charge when left idle. As the battery’s charge decreases, it becomes harder for your mower to start (source).

Additionally, if the battery was not fully charged when you last used it, it will have lost even more of its charge while sitting. If your mower doesn’t start after winter, try charging the battery to see if that helps. 

Note: If your battery is completely drained and can’t be recharged, you’ll need to replace it. 

The Lawnmower’s Gas Has Gone Bad

When gas sits for an extended period, it can become stale and lose its combustibility. Gas contains hydrocarbons that react with oxygen to create combustion inside the engine’s cylinder. 

But if these chemicals break down over time due to heat or exposure to air, they won’t vaporize as quickly, resulting in your mower not starting after winter. 

Below are several warning signs that indicate your lawnmower’s gas has gone bad: 

  • You notice a sour or pungent smell. If you notice an unpleasant odor coming from your mower, then the gas is probably stale. 
  • Your lawnmower’s gas is muddy or darker in appearance. Normal gasoline is greenish, bluish, or pink. If the gas has a dark, muddy appearance, it’s time to replace it with fresh fuel (source). 
  • You can’t remember when you last filled the mower with gas. If you can’t remember when you filled your lawn mower last and have no way of telling if the gas is stale, err on the side of caution and simply replace it. It’s better to replace the gas than to damage your engine. 

The Spark Plug Is Dirty or Corroded

Your lawnmower has an electrical ignition system that generates a spark between the plug and the cylinder, creating combustion. If this spark isn’t produced, then your lawnmower won’t start after winter. 

The plug must be clean in order to create the spark necessary for combustion. When your lawnmower sits, dust and debris can accumulate around the plug. The dust and debris accumulation will prevent the spark from passing between the cylinder and plug, meaning your lawnmower won’t start after winter. 

Your Lawnmower’s Air Filter Is Clogged

If you try to start your lawnmower, but it only sputters, then it’s probably due to a clogged air filter. The air filter is responsible for trapping dust and debris, preventing them from entering the engine. When your lawnmower sits unused throughout winter, this dust can accumulate on the filter, preventing adequate airflow, meaning your lawnmower won’t start afterward. 

To check for a clogged air filter, you should remove the housing and check for dust or debris. If you find any particles stuck to the filter, carefully remove them with a soft brush. 

The Carburetor Is Clogged

Your lawnmower has a small device called the carburetor, responsible for mixing air and gas so that combustion can happen. If this device becomes clogged with old gas, dust, or debris, it won’t perform its job adequately, meaning your lawnmower won’t start after winter. 

If there’s no obstruction in the intake port and you’re sure that your carburetor isn’t dirty, it may then be time to replace the entire carburetor. 

The Belt Has Come Off or Snapped

Most modern mowers have a belt that turns the blades to chop grass before passing through the chute at the bottom of the deck. If this belt becomes damaged or comes off, your lawnmower won’t start after winter. 

If you hear a strange noise coming from the engine, it’s likely that the belt is broken or has come off. Additionally, you should check for the following symptoms of a broken belt: 

  • The blades won’t turn. A broken belt won’t allow the lawnmower to move forward. 
  • The belt is cracked. Broken belts have sharp edges that can cause cracks or other damage. 
  • The belt’s sidewall is damaged. If the belt isn’t completely broken, then the sidewall may be damaged. It can lead to slipping and damage to other components. 

Your Lawnmower’s Ignition Switch Is Defective

An ignition switch is responsible for ensuring that electricity reaches all of the components in your lawnmower. 

If this switch malfunctions, the lawnmower won’t turn on when you pull the start cord, hence the equipment refuses to start after winter. 

If your mower won’t start after winter and you suspect that the ignition switch is defective, check for signs of water or mechanical damage. You can also inspect the wiring to ensure that all connections are secure.

The Blades Are Clogged

Your lawnmower’s blades are responsible for cutting grass, meaning they must move at high speeds to cut efficiently. When your lawnmower sits unused throughout winter, leaves and grass can accumulate around the blade housing, preventing the blades from spinning freely. This problem then causes your lawnmower not to start after winter. 

You can resolve this problem by cleaning the blade housing and removing any debris that may be stuck in the blades. If you need to replace your blade, make sure to match it with your mower model before buying it—different models require different blades. 

How Do I Get My Lawnmower Started After Winter?

Now that you know why your lawnmower won’t start after winter, it’s time to learn how to fix the problem.

You can get your lawnmower started after winter by doing the following:

  • Charge or change the battery. 
  • Drain the old gas and replace it with fresh gas. 
  • Clean the spark plug. 
  • Check the air filter. 
  • Check the carburetor. 
  • Inspect and replace the belt. 
  • Check the ignition switch. 
  • Clean the blades. 

Here’s how to go about each of the mentioned methods:

Charge or Change the Battery

If your mower uses a battery, check to see if it needs to be charged before trying to get the mower started after winter. A standard charge will do the trick in most cases, but read your manual for specific instructions on how often you need to recharge your lawnmower.

However, if the battery is worn out beyond repair, the only way to replace it. 

Drain the Old Gas and Replace It With Fresh Gas

To fix the problem of stale gas stopping your mower from starting after winter, you need to drain and replace the old gas with fresh fuel. To drain the fuel tank, locate the drain plug at the bottom of the tank—it’ll typically be below or beside the gas cap. 

Place a large container below the mower, then unscrew the gas cap on top of it. Use a hose or pipette to siphon all old gas out of the fuel tank. 

Once all of the gas has drained out, replace it with fresh fuel. To do this, follow the steps below:

  1. Remove the gas cap. 
  2. Pour in fresh fuel. 
  3. Replace the cap. 

Clean the Spark Plug

Next, check your spark plug to see if it’s dirty or corroded. If the metal has turned black and has a crusty texture, you need to replace the plug as soon as possible. 

Use a wire brush to scrub away any corrosion or debris to clean the plug. Replace your spark plug with an exact model that matches your lawnmower—don’t use a knockoff. 

Check the Air Filter

If you suspect that your air filter has become clogged, then remove it and inspect it closely. You may need to gently tap or brush away any dirt or debris to get it functioning correctly again. 

Alternatively, you can purchase a new air filter and install it according to your lawnmower’s instructions. 

Check the Carburetor

If your lawnmower has a carburetor, you’ll need to remove the intake port before trying to get the lawnmower started after winter. Once you’ve done that, use an aerosol spray lubricant or a small amount of WD-40 to coat the parts. 

Follow these steps to clean your carburetor safely: 

  1. Turn off the lawnmower. 
  2. Unplug the spark plug. 
  3. Unscrew the air filter, carburetor cover, and intake port. 
  4. Remove any dirt or debris inside your intake port using a wire brush or canned air. 
  5. Clean the inside of the port by spraying it with WD-40. 
  6. Replace all parts and reassemble your mower before trying to start it up. 

Inspect and Replace the Belt

If you suspect that your lawnmower’s belt is broken or no longer attached to the lawnmower, you need to inspect the belt immediately. If it’s cracked, frayed, or has slipped off of its pulleys, replace it before trying to get your lawnmower started after winter. 

Note: Ensure that your replacement belt is an exact match for the old one. Otherwise, your lawnmower won’t function properly. 

Check the Ignition Switch

If you suspect that your ignition switch is malfunctioning, then there’s an easy way to test it before buying a replacement. Flip the lawnmower’s kill switch back and forth to see if the engine starts up. If it starts up with no issues, then your ignition switch is working as it should. 

However, if you can’t get the lawnmower to start with the old kill switch, you may need a new one. To replace your old ignition switch, follow these steps: 

  1. Turn off the lawnmower. 
  2. Disconnect the battery. 
  3. Unscrew the bolts on the switch housing. 
  4. Remove the old switch. 
  5. Replace it with a new ignition switch. 
  6. Reconnect the battery and turn on the mower to test if the new switch is working. 

This video by Sears PartsDirect describes these steps in detail: 

Replacing an Ignition Switch on a Riding Lawn Mower

Clean the Blades

As I mentioned, your lawnmower won’t spin if it’s clogged with twigs and other debris. To fix this problem, you need to follow these steps: 

  1. Turn off the lawnmower. 
  2. Remove the spark plug. 
  3. Unscrew the blade bolt. 
  4. Take out the blades and clean them thoroughly with WD-40 and a wire brush. 
  5. Reattach your blades, plug in your lawnmower, and attempt to start it up again. 

Your lawnmower should turn on as long as you’ve done everything right. Otherwise, consider calling a professional or buying a new lawnmower. 

How To Winterize and Store Your Lawn Mower

Knowing how to store a lawnmower during winter is essential. After all, you wouldn’t want your lawnmower’s engine to break down due to poor storage. 

Here are some tips on how to winterize and store your lawnmower safely (source): 

  • Use a fuel stabilizer. Before you leave your lawnmower outside, put a small amount of fuel stabilizer in the tank to keep it from going stale. A stabilizer will keep moisture from ruining the fuel before spring starts. In this case, I recommend this STA-BIL Storage Fuel Stabilizer (link to Amazon). It keeps gasoline fresh for up to 24 months, besides preventing your tank from corroding. 
  • Remove the battery. For a battery-powered lawnmower, remove the battery and store it safely indoors. Ideally, it would be best to store it in a cool and dry place. 
  • Clean the lawnmower before putting it in storage. Clean your lawnmower thoroughly to eliminate any grime and debris. Make sure that your lawnmower is dry before you put it in storage. 
  • Store the lawnmower in a dry and well-ventilated spot. Consider keeping your lawnmower in the garage. Doing so will help prevent mold and corrosion. 


Here’s a roundup of the things that you should do to get your lawnmower started after winter: 

  • Recharge or replace the battery if necessary. 
  • Dispose of the old gasoline and refill with fresh gas. 
  • Test and replace the spark plug if necessary. 
  • Clean the carburetor, intake port, air filter, and blades. 
  • Replace the belt if it’s broken. 
  • Test and replace your ignition switch if necessary. 

If you have taken these steps, you should have no problem starting up your mower again. However, if these don’t work, consider hiring a professional to help or buying a new mower. Good luck! 

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