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16 Reasons Your Walker Lawn Mower Won’t Start

Your Walker lawn mower keeps your lawn looking its best. Without it, your lawn will quickly become overgrown affecting your home’s pristine outdoor appearance. You need to find the reason your lawn mower isn’t starting and fix it before your lawn turns into an overgrown field.

A Walker lawn mower won’t start when it isn’t getting fuel due to old gas, a plugged fuel filter, clogged fuel lines, bad fuel pump or a dirty carburetor. A plugged air filter preventing air from getting to the engine, a bad spark plug or a faulty electrical system will also cause a Walker lawn mower not to start.

Keep reading for more items that can prevent your Walker lawn mower from starting. You will find causes and information on how to fix the problem so you can get back to mowing.

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Follow all safety instructions provided in your equipment operator’s manual prior to diagnosing, repairing or operating. Consult a professional if you don’t have the skills, knowledge or are not in the condition to perform the repair safely.

Reasons Your Walker Lawn Mower Won’t Start

Empty Fuel Tank Will Cause Your Walker Mower Not to Start

Out of frustration, you may have overlooked checking the fuel level. It’s easy to skip the simple things and jump into the bigger items. Even if you filled up with fuel recently, you could have developed a fuel leak and not have noticed you were going through fuel quicker than normal.

Solution: Add fresh fuel to your fuel tank. Check for fuel leaks on your Walker lawn mower and repair as needed.

Old Fuel Will Cause Your Walker Mower Not to Start

Type of Gas to Use in Your Walker Lawn Mower

A gas-powered Walker lawn mower uses unleaded gasoline with an ethanol content 10 percent or less and an octane rating of 87 or higher. This is gas sold as Regular gas or E10 gas at most fuel stations. Do not use a gas with a higher ethanol content.

The lower ethanol content your fuel has, the better. Ethanol is not good for the small engine used on a Walker mower. Read my article on the type of gas lawn mowers use for more details on choosing and storing the right gas.

Use Fresh Fuel in a Walker Lawn Mower

Old gasoline in a gas-powered Walker lawn mower can prevent your mower from starting. Gasoline can become less effective and breakdown as soon as 30 days after purchase. Never use gasoline with high ethanol contents like those sold as E15, E30 and E85 fuel.

The moisture ethanol attracts will leave gummy deposits in the fuel system as the ethanol and moisture mixture evaporates. This will clog fuel components keeping your engine from getting the fuel it requires to form a combustion and start.

Solution: Drain the fuel tank using a fuel siphon pump. Add fresh gasoline with a fuel additive to stabilize your fuel and clean your fuel system like Sea Foam Motor Treatment.

Bad Fuel Cap Will Cause a Walker Mower Not to Start

Check the fuel cap when your Walker mower won’t start. The cap is designed with a vent to allow air to pass through the cap to equalize the pressure in the fuel tank. When the vent is plugged, the fuel tank will form a vacuum keeping fuel from leaving the tank and getting to the engine.

To find out if your gas cap is broke and no longer venting, troubleshoot it by removing the cap and starting your lawn mower. If it starts with the cap removed allowing a air to enter the fuel, reinstall the fuel cap. Allow it to continue to run with the potential bad cap to see if it the engine will eventually run sluggish and die because of a lack of fuel.

If it does die and starts up again once after you remove the fuel cap again, you most likely have a bad fuel cap.

Solution: Replace a bad fuel cap with a new one.

Bad Spark Plug or Loose Connection Will Cause a Walker Mower Not to Start 

A spark plug can become covered with dirt, carbon and oil that will cause intermittent starting and running problems. A spark plug that is damaged, not gapped correctly or one where the spark plug wires are not attached securely can prevent your mower from starting.

Solution: Remove the spark plug(s) from your Walker mower. Inspect it for signs of buildup, a cracked porcelain insulator or burnt electrode. If you find any of these items, it is best to replace the spark plug with a new one.

If your spark plug is in good condition, but just slightly dirty, clean it with a wire brush. Check the gap of the spark plug using a feeler gauge. Make sure it is gapped to the engine manufacturer’s specification. Install the spark plug and securely attach the spark plug wire so it makes good connection.

Plugged Air Filter Will Cause a Walker Mower Not to Start

The engine requires clean air to run. Dirt and debris that gets into the engine can cause significant engine damage. The air filter used in your Walker lawn mower keeps dirt from entering the air intake so the engine only gets clean air.

Because of the dusty and dirty conditions created when mowing the lawn, the air filter can become plugged, restricting the amount of air passing through the filter when it isn’t regularly cleaned or replaced. I recommend replacing the air filter annually and then cleaning it several times throughout the season.

Never use your Walker mower without an air filter, even if it’s just to get done with your current mowing task until you can get a new replacement filter. Again, doing so will put you at risk of causing engine damage.

Solution: Inspect the air filter to see if it needs to be replaced or if you can clean and reuse it.

Clean a Walker lawn mower paper air filter:

  • Remove your paper air filter from the air filter housing.
  • Wipe out any remaining dirt in the housing being careful not to allow dirt to fall into the air intake.
  • Tap your air filter against a solid surface to loosen dirt and remove it from the filter. Do not use compressed air to clean the filter as this can damage the paper element.
  • Hold your clean filter up to a light source. If you can see light shine through the paper element, it is safe to reuse it. If you don’t see light, you must replace your old filter with a new one.
  • Install the cleaned or new air filter and attach the air filter housing cover.

For directions to clean other types of air filters, refer to “Guide to Lawn Mower Air Filters“.

Plugged Fuel Filter Will Cause a Walker Mower Not to Start

Check your Walker mower’s fuel filter. The fuel filter is installed to screen the dirt from the gas coming out of the fuel tank and prevent it from entering the fuel system. A plugged filter will restrict flow preventing your Walker mower from starting when it can’t get fuel to ignite.

It’s good practice to replace the fuel filter annually. You may have to change it more often when running dirty fuel.

Solution: Replace a filter that is plugged, damaged or leaking. When installing an inline fuel filter, pay attention to the arrow on the filter. The filter must be installed with this arrow pointed in the direction of the mower’s fuel flow.

Bad Fuel Pump Will Cause a Walker Mower Not to Start

A fuel pump is used to pump gas to the carburetor. When the pump is no longer able to build pressure using the vacuum in the crankcase to push fuel to the carburetor, it must be replaced.

Sometimes you can visibly recognize damage. The housing may have small crack or fuel may be leaking from the seams when a pump is bad. Other times you will have to test fuel flow to determine if the fault of your Walker lawn mower’s starting problem is the due to a bad fuel pump.

While there are different types of fuel pumps, most lawn mowers use vacuum fuel pumps. You may also find electric or electronic fuel pumps as well. Make sure you are getting power to the pump and consult with your engine dealer on specific testing procedures and pressure specifications for these types of fuel pumps.

Solution: To identify you have a bad vacuum fuel pump, first verify you are getting fuel flow to the fuel pump by checking for fuel out of the line connected to the inlet port on the pump. Once you confirm you are getting fuel to the pump, you will proceed with testing the pump to make sure a steady or pulsating flow of gas is being pumped out of your fuel pump.

Use the fuel shut-off valve or fuel clamps to start and stop flow to test fuel flow. You can also use hose pinch pliers to crimp the line to stop flow. With the fuel flow stopped, remove the fuel line from the carburetor and place it in a container.

Start your fuel flow and start your mower. Watch for a steady or pulsating flow out of the line into the container. If you aren’t getting sufficient fuel flow, your fuel pump may be damaged and will need to be replaced.

Clogged Fuel Line Will Cause a Walker Mower Not to Start

Running old fuel can cause deposits to stick to your fuel lines restricting the amount of fuel that is able to flow through the lines. Without a sufficient source of fuel, you Walker mower won’t start.

Check for a blockage in your fuel line by stopping your fuel flow, removing the end of hose from a section of fuel line furthest from the fuel tank. Place the hose in a container and start the fuel flow.

Make sure the container is placed lower than the fuel tank. Fuel cannot run uphill without the help of a fuel pump. If you are not getting sufficient flow, you will need to remove the line and remove the restriction.

Solution: Remove the fuel line from the mower and spray carburetor cleaner into the line. This is used to loosen up the clog. Next, use compressed air to blow air through the line until the blockages is removed. If you are unable to clear the clog or you notice your fuel line is beginning to crack, you will need to replace the fuel line.

Dirty Carburetor Will Cause a Walker Mower Not to Start

Your carburetor can become dirty from running old fuel through your lawn mower. Fuel can leave a varnish in your Walker mower carburetor. This can plug the fuel jet or cause the small parts in your carburetor to stick and not function properly.

A carburetor’s main job is to regulate the amount of fuel is mixed with air to form a combustion in your engine’s cylinder.

Solution: If you are a little mechanical you should be able to handle cleaning your carburetor. Clean the carburetor by taking it apart and using carburetor cleaner to clean the carburetor including the float bowl and needle.

You can find steps for cleaning your carburetor here. If your carburetor is too dirty to clean adequately, you should replace it.

Bad Battery, Loose Cables or Corroded Terminals on a Walker Lawn Mower

A Walker mower will not start with a bad battery, loose cables or corroded terminals. Confirm your battery terminals are not corroded and are attached securely to the battery.

Solution: Clean corroded terminals in a baking soda solution containing 2 cups of water and 3 rounded tablespoons of baking soda. Use a wire brush to scrub the terminals clean.

Test your battery with a multimeter. You will want a reading at about 12.7 volts. Place on a charger to charge your battery if your reading is less than this. Read more about the steps and items needed to charge your battery here. If your battery does not hold a charge, you will need to replace it with a new battery. 

Bad Safety Switch Will Cause a Walker Mower Not to Start

Your Walker lawn mower may use several safety switches designed to keep the operator safe. The manufacturer installs safety switches to prevent the mower deck to run without the operator present.

It also has a safety switch involved to not start when your parking break isn’t engaged. If these safety switches fail, your mower may not start.

Solution: Test the switch using a multimeter or you can temporarily bypass the safety switch to identify a bad switch. 

Do not operate a mower without the safety switch. Never run a mower when a safety switch is bypassed. You never know when you will encounter a situation where the safety switch can save you from serious injury.

Bad Ignition Switch Will Cause a Walker Mower Not to Start

You insert the key into your ignition switch and turn it only to find your Walker mower doesn’t start or even turn over. The ignition switch could be the problem.

Solution: You can use a multimeter to test the ignition switch. Replace the switch if bad.

Bad Ignition Coil Will Cause a Walker Mower Not to Start

The ignition coil provides voltage to the spark plug so it can fire and start the engine. The engine will not start if the spark plug isn’t able to fire.   

Solution: After you verified your spark plug is in good condition, check the continuity of your ignition coil using a multimeter. Replace the ignition coil if you find a break in the continuity.  

Faulty Charging System Will Cause a Walker Mower Not to Start

A charging system that is no longer able to keep your Walker mower running can cause it to die while you are mowing. It can also cause your battery to be drained preventing it from starting the next time you go to use your mower. A bad stator or alternator can be the problem. I show steps on how to test your charging system here using an ohm meter.  

Solution: When you find your Walker’s starting problem is due to the charging system, take your lawn mower to your local Walker dealer for further troubleshooting and repair.

If you don’t have experience with charging systems, you will most likely just throwing different parts at your mower hoping to fix it. The cost of all of these parts can get pretty expensive if you don’t guess right the first time. Most lawn mower centers do not allow you to return electrical parts so you will be stuck with the part whether it is the problem or not.

Incorrect Operating Procedure Will Cause a Walker Mower Not to Start

The are certain starting procedures that must take place in order to start and run your Walker mower. This includes setting the parking brake, placing your steering lever in the neutral position, and making sure your PTO is not engaged. If you don’t have any of these items in the right position, your Walker mower will not start.

Another item that can prevent your mower from starting when not in the correct position is the choke control lever. The choke lever must be in the on position to start a cold engine. The choke restricts the amount of air that is allowed to be mixed with fuel to form a combustion.

It allows a higher concentration of gas needed to start a cold engine. Once your engine starts and warms up, you will begin to move the choke lever to the off position. If you don’t adjust the choke to the off position once the engine has warmed, you will find the engine will run sluggish and die.

Solution: Refer to your Walker mower operator’s manual for your model mower. Ensure you are starting your lawn mower correctly so you don’t set off the safety features that shut off your lawn mower. 

Bad Fuse Will Cause a Walker Mower Not to Start

Your Walker lawn mower uses fuses to protect your mower’s electrical system. The fuses are located under the seat panel.

Solution: Replace your blown fuse. Use a fuse with the same amperage of the fuse you are replacing. If you continue to blow fuses, you should bring your Walker mower to your local repair shop or your local Walker mower dealership to troubleshoot the root cause of the electrical failure.