Your grass doesn’t stop growing. So when your mower stops running, you need to find and fix your problem before your yard gets out of hand.
A Walker lawn mower may start then die due to a plugged fuel filter, clogged fuel line, bad fuel pump, dirty carburetor, plugged air filter, bad spark plug, incorrect engine oil level, bad gas cap, plugged mower deck, or bad gasoline.
Keep reading for additional items that can cause a Walker walk-behind, zero-turn, or stand-on to quit running. Remove the spark plug wire and ignition key before performing any repairs.
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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.
Your Walker Zero Turn Starts Then Dies (Find & Fix!)
1. Bad or Old Fuel
When gas isn’t consumed right away it can be bad for the fuel system causing fuel restrictions and component failures.
Most gasoline sold today contains ethanol. This is an alternative fuel that is usually made from corn or another high-starch plant.
While ethanol is added to gas to make it more environmentally friendly, it is not good for the small engine on your Walker zero-turn.
Ethanol attracts moisture from the air to the fuel system causing corrosion in the fuel system. When the mixture separates from the gas and evaporates, it leaves behind gummy deposits that can cause clogging that restricts fuel flow to the engine.
Clogged fuel components prevent your Walker mower from getting the fuel it needs to continue to run.
Tips for selecting and storing gas for your Walker mower:
- Select a gas that has a minimum 87-octane rating.
- Make sure it contains no more than 10% ethanol (E10). Stay away from fuels sold as E15 and E85.
- Purchase fresh gas and consume it within 30 days.
- Use a fuel additive to keep the fuel stable longer.
- Store fuel away from combustible products and in a dry location.
SOLUTION: If your mower has old fuel in the tank, drain the tank using a fuel siphon pump into an approved gas container. Fill the fuel tank with the right gasoline with a fuel additive mixed in to stabilize the gas.
I use Sea Foam Motor Treatment in each tank of fuel. It stabilizes the fuel, reduces moisture, and cleans the fuel system. It’s a safe petroleum-based product for your zero-turn. Read more about the positive effects of Sea Foam here.
2. Clogged Fuel Filter
An inline fuel filter is placed between the fuel lines on a Walker mower. Its purpose is to strain fuel to keep dirt and debris from getting into the fuel system.
When the fuel filter isn’t changed out regularly, it can become plugged with dirt so a sufficient amount of fuel isn’t able to pass through the filter. The mower may begin to run sluggishly and die.
SOLUTION: Replace a plugged fuel filter. When installing the new filter, ensure the arrow shown on the side of the filter housing is pointed in the direction of the fuel flow. You will find an arrow on most fuel filters.
3. Clogged Fuel Lines
Old fuel can leave behind a substance that may build up and clog the fuel line. The engine will die without enough fuel.
SOLUTION: Check for blockages in your fuel lines using the fuel shut-off valve to start and stop fuel flow while checking each section of the fuel line for fuel flow.
If you find a fuel line that has a blockage, turn off the fuel supply and remove the fuel line from the mower.
Spray carburetor cleaner into the fuel line to loosen up the clog. Follow this by blowing compressed air through the line to remove the blockage.
If you are unable to dislodge the blockage to open the fuel line, install a new fuel line on your mower and turn on your fuel supply.
4. Bad Fuel Pump
Most fuel pumps used on Walker zero-turn mowers are vacuum pumps. They use the vacuum off the engine to draw fuel from the fuel tank and move it to the carburetor. Pumps can fail after time from wear or they can begin to degrade from fuel.
SOLUTION: To determine you have a bad fuel pump, confirm you are getting fuel flow to the fuel pump by checking flow through the fuel line. You may have done this in the prior step.
Next, check the fuel flow out from the fuel pump. Turn off your fuel flow and remove the fuel line from the carburetor. With the line placed in a container, turn on your fuel flow and start your zero-turn.
Watch for a steady or pulsating flow of fuel out of the line indicating your pump is working. If you don’t get a good flow, replace the fuel pump.
If your Walker has an electronic fuel injection pump, obtain a pressure reading using a fuel pressure gauge. Refer to your operator’s manual for the fuel pressure specifications.
5. Dirty Carburetor
The carburetor regulates the amount of gas that is mixed with air and allowed into the cylinder to form combustion.
The components on your Walker carburetor can become clogged and fail to release the amount of fuel your engine needs to run causing it to run sluggishly or die.
SOLUTION: Before you disassemble and clean your carburetor perform these simple checks to determine the problem is in your carburetor:
- Confirm you have fuel flow to the carburetor. You should have verified this if you check the fuel flow out of your fuel pump.
- Remove your air filter from the air filter housing.
- Spray carburetor cleaner into the air intake and start your mower.
- If the Walker zero turn starts, runs fine, and then shuts down, your problem may be in the carburetor.
Remove the carburetor to disassemble it and clean the carburetor using the steps listed here. Bring your mower to a small engine repair shop if you choose to have someone else tackle this job for you.
6. Clogged Air Filter
Just like the engine needs a sufficient amount of fuel to start and run well, it also needs a sufficient amount of air. A plugged air filter can keep your Walker mower from getting good airflow.
The dust and grass clippings that get tossed into the air can get pulled into the zero-turn and wear on the engine when the air filter is not in place. It’s important to have a clean air filter installed in the mower at all times.
I recommend replacing the air filter annually if you use your mower like the average homeowner. If you use your mower for commercial purposes or very often, it’s best to replace it more often.
Your air filter maintenance doesn’t stop there. You must check it before each use of the mower and clean it when required. It only takes a minute or two to do this.
Skipping this step can cause the engine to overheat when it becomes plugged.
SOLUTION: Follow these instructions to check and clean your paper air filter:
Clean a Walker mower PAPER air filter:
- Remove your paper air filter element from the housing.
- Wipe out any dirt remaining in the housing with a clean dry cloth. Don’t allow dirt to fall into the air intake.
- Tap it against a hard surface to remove as much dirt as possible to fall out of the filter. Don’t use compressed air as this will damage the paper.
- Hold your filter up to a light source. Replace your filter with a new one if the light is not shining through the paper element or it is damaged. If it is, go ahead and reuse it.
- Install your air filter and reattach the filter housing cover.
7. Dirty Engine Cooling Fins & Cooling System
The engine can overheat after it has been running a while causing your Walker mower to die. One of the items that can cause overheating is plugged engine cooling fins.
The fins need to be kept clean and free of debris so they can efficiently push air around the engine block and cylinder head to keep it cool.
SOLUTION: Remove any dirt you find on your cooling fins and replace any broken fins.
Remove dirt from around your engine block and around your engine shroud. Make sure your heat shield is correctly installed to help with air circulation.
8. Low Engine Oil Level
It’s important to check the engine oil level in your Walker zero-turn mower before each use. Many mower owners skip this step. Checking the engine oil level using the oil dipstick is a fairly quick process.
Catching a low engine level before it causes engine damage can save you from a costly repair expense. Running your zero-turn with a low engine level can cause your mower to overheat and shut down.
When there isn’t enough engine oil to lubricate the internal engine components, friction among the parts will build creating heat in the crankcase. This excessive heat can begin burning oil and parts in your engine.
SOLUTION: When you run into a problem with your mower shutting down due to a low engine oil level, you can attempt to add more oil to correct the level and start your mower.
Most of the time, if your mower shut down because of a lack of lubrication, the simple fix of adding more engine oil isn’t going to work.
Most likely, significant engine damage was caused. It is best to have an experienced small engine mechanic take a look at your mower to find out how much damage occurred.
9. Too Much Engine Oil
Not only can low engine oil cause your engine to die, but also too much engine oil can make your zero-turn shut down. Excess oil will cause pressure to build in the crankcase.
SOLUTION: If you find, after checking your engine oil, that your level is too high, remove a little bit of oil. Oil can be removed from the drain plug, oil filter, or from the oil fill area using an oil evacuator or turkey baster.
Continue to remove and add engine oil until the level is corrected.
10. Dirty Spark Plug or Loose Connections
A fouled spark plug can cause your Walker mower to die. An incorrect electrode gap or loose spark plug wire can also cause this problem.
SOLUTION: Remove your spark plug and clean the spark plug with a wire brush if it is dirty. If it happens to be very dark in color or damaged, install a new spark plug.
Ensure the plug is correctly gapped according to the engine manufacturer’s specification and the spark plug wires are securely attached.
11. Bad Ignition Coil
The windings on the ignition coil can separate and short out when the mower is hot. When this happens, the spark plug is unable to get the voltage they need to create a spark.
This can cause your Walker mower to die after it’s been running for a while.
SOLUTION: Identify a bad ignition coil using an ohmmeter to check for a break in continuity. Replace the ignition coil if you find there is a break.
12. Bad Safety Switch
Your Walker has an operator presence control system installed to keep you safe. This is a system that includes safety switches to prevent a mower from starting if certain events are not met like engaging the brake.
A safety switch can be defective and cause your Walker to fail to turn over. Test your switch using a multimeter. The seat switch, brake switch, and PTO switch may be bad.
SOLUTION: Consult your operator’s manual for additional safety switches installed on your mower.
You can also temporarily bypass the safety switch to identify a bad switch but only do this for troubleshooting purposes.
Never operate a mower without the safety switch. Never run a mower when a safety switch is bypassed. A safety switch can save you from serious injury and you never know when you’re going to need it.
13. Choke in the Wrong Position
Your Walker requires a choke to restrict airflow to allow more fuel into the combustion chamber. This is needed to start the engine when it is cold.
SOLUTION: If you leave the choke on after the engine heats up, your mower will die. The choke must be adjusted to the open/off position once the engine warms. Make sure your choke lever is in the right position.
14. Bad Gas Cap
The fuel tank on a Walker mower must be able to vent. When there isn’t a vent, the tank will form a vacuum that keeps fuel from flowing out of the tank into the fuel lines and the mower will die.
SOLUTION: You may have a bad gas cap when you find the mower shuts down and won’t restart until you loosen the cap to allow air into the fuel tank.
15. Plugged Mower Deck
A plugged Walker mower deck can make your engine work hard, overheat and shut down.
When grass collects under your mower deck, extra strain is put on the engine when it must turn the blades through a deck full of debris. Dull mower blades can further magnify the problem.
SOLUTION: Regularly scrape your mower deck and sharpen your mower blades. Not only will a clean deck not put extra strain on your engine, but it will also provide you with a nicer cut.
The deck uses the blades and area under the deck to create air movement to lift and cut your grass.
Remember to take additional precautions when working with sharp blades and under the mower deck.
Protect your hands, remove the ignition switch, disconnect the spark plug wire, and follow all additional safety precautions provided in your Walker operator’s manual.
Why is My Walker Lawn Mower Battery Not Charging?
Make sure you are running your Walker mower at a high engine speed. Don’t allow your mower to idle for long periods. It requires the power of the engine to charge your battery.
If you continually have to charge your battery and have confirmed the battery and wiring are in good condition and securely attached, you may have a problem with the charging system.
SOLUTION: There are some steps you can take to check the condition of your battery and charging system which I explain in this article. If after performing these tests, you find you have a bad battery, replace your battery.
When you find the charging system isn’t working right, I highly recommend having an experienced mechanic diagnose and repair the problem.
There are so many components that can cause the charging system to fail that, unless you know the charging system, parts can be thrown at it hoping it repairs the issue.
Electrical components can get expensive and they most likely can’t be returned because most stores have a policy where electrical items cannot be returned.