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Black+Decker Lawnmower Starting Problems. Troubleshoot&Fixes

For homeowners, lawnmowers are of great utility since they can help maintain gardens and tidy up overgrown grass with lesser effort. But it can be a nuisance when you try to start your lawnmower after a while, and it would not start. Let’s learn how to fix a Black+Decker lawnmower that fails to start or stops after starting. 

Black+Decker Lawnmower Starting Problems:

A gas-powered Black Decker Lawnmower may fail to start due to a bad spark plug, a defective ignition system, a plugged carburetor, or blocked filters with excessive deposition of fuel and dust. In some rare cases, a sheared flywheel key can prevent the engine from engaging the drive mechanism, and the mower may not work. If you have electric-powered variants, ensure the electrical connections are secure, the batteries are charged, and the starting switches are working correctly.

The factors mentioned above are probably why your lawnmower fails to start. If you want to learn how to restore your machine to its original state without consulting a mechanic, scroll down to read more.

Black-Decker Electric Lawnmowers:

Corded electric lawnmowers are quieter and require lesser upkeep than traditional gas-powered variants. However, they do have a limited range despite having an extension cord.

The following are the most common starting problems in these devices:

1. Electric Lawnmower Doesn’t Start?

Remove the extension cable if the electric lawnmower doesn’t start by plugging it directly into the socket. Make sure the socket is working, and the fuse is still ok.

Using a multimeter, you should check the power cord for a continuity test. Check for a tripped circuit breaker in your house besides blown fuses and faulty switches. A sudden voltage surge by the lawnmower motor may have engaged the circuit breaker causing it not to start.

If all the switches are working correctly and the power cable isn’t faulty, you should contact customer support and get the motor checked, as it’s most likely the probable cause of the problem.

2. Electric Lawnmower Shuts Down?

An electric lawn mower can fail suddenly for one of three reasons

  • The power switch has burnt out.
  • The circuit breaker has tripped and stopped the current.
  • The overheated motor has tripped the thermal cut. 

Check all the wires for any loss of insulation or broken/loose connections. If the wires work fine, the fault is likely with the motor. The motor could be overheated if each of these is functional. In that case, please turn off the machine and give it 10 to 20 minutes to cool.

If it still doesn’t start, consulting a professional is recommended. 

Black-Decker Battery Powered Lawnmowers:

One of the biggest pros of battery-powered machines is that they provide increased range (like gas mowers) and are easier to maintain and use (like electric mowers). Some of their common problems are:

1. Battery-Powered Lawnmower Doesn’t Start.

If a battery-powered lawnmower doesn’t start, the reason is probably a dead battery or a faulty charger. The start switch could also be burnt or get loose. In rare cases, the electric motor might be faulty.

You should check the battery, charger, start switch, and motor if your Black+Decker lawn mower won’t start.

– Solution:

  • Battery: First, check that the battery is correctly mounted on the lawnmower. It usually gives a click when you add it.
  • Corrosion: First, ensure the battery terminals aren’t corroded with residues. Ensure continuity and clean them with some alcohol or carefully with a metal brush. To check the voltage, you can use a digital multimeter. Check the terminal voltage, which should be close to the rated value.
  • Charger: You should test the charger by connecting a different battery or using a multimeter to ensure your battery charges correctly.
  • Start Switch: Run the continuity test on the start switch to check its connectivity.

2. Battery-Powered Lawnmower Shuts Down?

Check that the battery hasn’t run out. Ensure that the starting switch is working correctly. If these components are fine, the motor has probably malfunctioned.

Besides the battery and the switches, a thermal switch can cause your lawnmower to shut down. In that case, allow your lawnmower to cool down and start it after 15-20 minutes. If it’s still not working, you should ask the manufacturer for a motor repair/replacement if it’s under warranty.

Factors Causing Startup Problems in Gas-Powered Black+Decker Lawnmowers

Now let us discuss some of the major factors that need to be troubleshot and fixed for a gas-powered Black+Decker lawnmower to start.

Please perform these steps in the mentioned order. This helps identify the problematic components by starting with the simplest and most likely causes to the rarely occurring ones at the end.

1. Stale Fuel Issues:

Bad gas or old fuel may be present in the carburetor float bowl. Over time, some of the gasoline components may evaporate, leaving behind a thicker, stickier substance. 

This stale fuel may block the carburetor jets and prevent the engine from starting. It’s pretty likely that the fuel that remains gets sticky and ends up blocking the fuel jets, which can affect the air-fuel flow to the engine and reduce its power output.


Replacing the gas in your tank is recommended every few months if you use regular fuel. Or add fuel stabilizers and additives that prevent gas from getting bad and unwanted residues from clogging the fuel jets and the carburetor.

If the problem isn’t fixed after replenishing the old fuel, you may need to inspect the carburetor and clean it thoroughly from the debris stuck inside.

2. Clogged Carburetor

One of the main reasons why your lawnmower fails to start is because the carburetor jets are clogged with fuel debris. The air-fuel mixture formed by the carburetor is supplied to the engine for combustion. When it gets clogged, the engine’s combustion will be affected, thus causing problems in starting up.


The carburetor must be thoroughly cleaned with a carburetor cleaner fluid (or WD-40) and a thin metal wire for the mower to run seamlessly. Make sure the fuel jets are cleaned from white deposits. Don’t forget to clean the float bowl and the bowl nut, as it is a fuel jet. After cleaning, reassemble all the parts.

You should ask a professional for help if the carburetor still malfunctions after cleaning thoroughly. 

3. Foul Fuel/Air Filters

In most cases, air and fuel filters could also cause the mower not to start up properly.

The air filter on your lawnmower filters the dust and foreign particles, such as grass or something else, from the air. The engine gets deprived of air if the filter gets blocked with debris. Hence, it may not start properly or stall shortly after starting up.


I recommend replacing paper filters—or cleaning or replacing foam filters—every 25 hours of engine use to prevent this from occurring frequently. If the air filter is made of foam, I recommended to use hot water for washing and a soap solution to clean it from debris.

In the case of a fuel filter, you should remove it using nose pliers from the fuel tank and inspect its condition. If it has undergone significant wear and tear, replace the filter with an identical one.

If the problems remain, you should check the fuel tank for a vapor lock.

4. Vapor Lock

Fuel caps in most fuel tanks are designed with vents. The vents equalize fuel vapor pressure to allow fuel to flow from the tank to the carburetor. Without the vent, petrol fumes inside the tank accumulate, creating a vacuum in the fuel lines that block the fuel flow.


You should remove the fuel cap to release the vacuum. Then restart the engine to see if the issue is fixed or not. If the lawnmower starts again, the vapor lock is causing the problem. After that, you should clean your fuel caps vents thoroughly to make sure that the debris stuck has been removed.

5. Faulty Recoil Starter

Since all Black+Decker products are push mowers with pull cords, a faulty recoil starter is another fairly less common reason why your lawnmower doesn’t start. The recoil starter is a spring-pulley assembly that rotates the flywheel to start the engine after you pull the cord.

When the starter assembly gets faulty, the pull cord doesn’t work, and the engine doesn’t start.


In this case, you must inspect the recoil starter assembly by removing the blower housing. Check if the spiral spring works correctly by seeing if the pull cord winds or unwinds by itself. The most common issue can be a faulty or missing spiral spring.

In this case, replacing the damaged/missing components can solve the problem.

Black-Decker Self-Propelled Lawnmowers:

Here, I’ll discuss some of the typical startup issues that can occur in a gas-powered push lawnmower.

1. Self-Propelled Lawnmower Engine Doesn’t Start.

First, make sure you have fresh petrol in your tank. Starting issues can also result from using old gas. Drain your fuel tank and replace it with fresh gasoline if your mower still has last season’s fuel. Additional problematic causes include:

  • Spark plug: Spark Plug has become black with soot, has a damaged electrode, or is loose.
  • Filter: Make sure the air filter isn’t dirty with dust buildup.
  • Carburetor: If fuel isn’t getting to the engine, inspect the carburetor and service if there are signs of old fuel deposits in the carb jets.

2. Self-Propelled Lawnmower Pull Cord Doesn’t Work.

If the pull cord on your push mower is stuck, check the blades and remove any grass clippings stuck between the blade and the spindle. Also, a broken recoil assembly can make the pull cord inoperable.

The first thing to do is to check for any grass or debris stuck between the blades and the spindle. If the blades get stuck due to a foreign object, the shaft doesn’t rotate. The pull cord can also get stuck since the blade shaft is coupled with the crankshaft or flywheel.

Pull the starter rope while squeezing the brake lever once the mower’s underside is free of obstructions. The engine won’t start if the brake lever isn’t pressed while pulling the cord.

If the problem persists after cleaning the blade assembly, remove the blower housing to check the recoil assembly. Try to inspect the cable by pulling it some distance and releasing it. If it fails to restore, the recoil spring has failed and needs a replacement.

3. Self-Propelled Lawnmower Smoking?

If your gasoline-powered lawnmower emits white (or blue) smoke, it indicates that the engine oil is also being burnt alongside fuel in the cylinder.

The oil could have leaked into the combustion chamber from the crankcase when you turned your lawn mower on its side to change the blade, or perhaps you overfilled it when you changed the oil. In any event, burning oil is probably causing the white smoke. 

This problem only applies if your lawnmower engine is four-stroke, as two-stroke engines smoke quite often during normal operation.

– Solution:

You must remove any stray oil and ensure it is not leaking out if it has been overfilled. In some cases, worn-out piston rings cause oil to flow from the crankcase into the cylinder, particularly when the engine is old. The solution lies in getting your piston rings changed by a professional.

It is probably due to clogged air filters if you see black smoke instead of white or blue. Due to a reduced airflow to the engine, the air-fuel mixture becomes rich with fuel, which burns partially and produces black carbon smoke as a residue. 

4. Self-Propelled Lawnmower Runs Rough/Misfire?

If a lawnmower misfires, the ignition timing has been upset. Apart from that, there can be other issues with the spark plug and the carburetor to cause this problem. Here’s what you need to check:

  • Carburetor: The carburetor in your riding lawn mower can be blocked if the engine runs rough or misfires. In case the carburetor is clogged, rebuild it or replace it. 
  • Flywheel Key: Check the flywheel key if the engine is misfiring after running into a rock or stump. A broken flywheel key will throw off the ignition timing. You should consult a professional to get the flywheel key replaced, as this involves a slightly tricky disassembly.
  • Spark Plug: Check the spark plug for carbon and soot deposits. If the buildup is significant, the spark quality will be diminished. Replacing the plug is recommended in this case.

Lawnmower Starting Problems

1. Gas-Powered Lawnmower Starting Problems

Lawnmower doesn’t start
a. Empty fuel tank
b. Clogged carburetor
c. Air filter blocked with dirt.
d. Spark plug with worn-out electrodes
a. Before adding fresh, drain old fuel residues from the tank.
b. Inspect and clean the air and fuel filters from debris. Replace if necessary.
c. Disassemble and clean the carburetor using a carb. cleaner liquid.
d. Replace the spark plug if electrodes are worn out.
Lawnmower starts but then dies
a. Blocked air filter
b. Clogged carburetor jets
c. Vapor lock in the fuel tank
a. Clean the air filter using soap and water. Replace if needed.
b. Clean the carburetor jets from residues using a carb cleaner spray.
c. Clean the fuel tank vents to prevent a vapor lock.
Lawnmower is smoking
a. Oil leaking into the combustion chamber
b. Blocked air filter  
a. Avoid overfilling the oil tank.
b. Always tilt the mower with the air filter pointing upwards.
c. Check and replace worn-out gaskets.
d. Clean the air filter.
The lawnmower runs rough/misfires
a. Stale fuel deposits in the fuel system.
b. Broken flywheel key
a. Perform a complete tune-up involving cleaning the filters, carburetor, and fuel lines.
b. Replace the flywheel key.

2. Corded Electric Lawnmower Starting Problems

Lawnmower doesn’t start
a. Loose connection
b. Defective extension cord
c. Faulty start switch
d. Tripped circuit breaker
a. Ensure the connections aren’t loose and the socket is working.
b. Try plugging in directly without an extension cord.
c. Test the start switch using a multimeter and replace it if needed.
d. Reset the tripped circuit breaker.
The lawnmower shuts down during operation.
a. Loose plug at the socket
b. Tripped circuit breaker
c. Motor winding damage
a. Ensure the connection isn’t loose and the socket works.
b. Reset the circuit breaker or replace the blown switches.
c. Contact customer support to seek a replacement in case of motor damage.

3. Cordless Battery Powered Lawnmower Starting Problems

Lawnmower doesn’t start
a. Low battery
b. Faulty start switch  
a. Ensure the battery is fully charged.
b. Test the start switch for continuity using a multimeter.  
The lawnmower shuts down during operation.
a. Low battery
b. Overheating
c. Debris obstructing the blades  
a. Ensure the battery is fully charged.
b. Let the lawnmower cool down for 10-15 minutes and restart.
c. Clean the mower’s underside and remove any debris/grass clippings.

4. Robotic Lawnmower Starting Problems

Lawnmower doesn’t start
a. Disconnected boundary wire
b. Faulty power supply
c. Software update
d. Debris stuck in blades
a. Ensure the boundary wire is connected to the charging station.
b. The battery connections should be correct and the charging should be sufficient.
c. Keep the software up to date.
d. Remove any debris stuck between blades.
The lawnmower keeps shutting down mid-operation
a. Ensure the boundary wire is connected to the charging station.
b. The battery connections should be correct, and the charging should be sufficient.
c. Keep the software up to date.
d. Remove any debris stuck between blades.
a. Avoid mowing when the conditions are damp.
b. Resolve error messages on the display.
  1. Layla Stone says:

    Can using fuel additives prevent starting issues in a lawnmower?

    • Allard Vdhooft says:

      Yes, using fuel additives can help prevent starting issues in a lawnmower by keeping the fuel system clean and preventing clogs. It’s a good option to try before consulting a mechanic.

  2. Howard Morgan says:

    I never knew there were so many components in a lawnmower that could cause starting problems.

    • Allard Vdhooft says:

      Glad to help you understand the complexities of lawnmower starting issues! Feel free to reach out if you have any more questions or need further assistance.

  3. Brianna Brown says:

    The step-by-step solutions make it easier for beginners like me to understand and fix lawnmower issues.

    • Allard Vdhooft says:

      Thank you for your feedback, Brianna! I’m glad the step-by-step solutions are helpful for beginners like you. Feel free to reach out if you have any more questions or need further assistance.

  4. Tomothy Stewart says:

    Great video resources provided for visual learners to understand the troubleshooting process better.

    • Allard Vdhooft says:

      Thank you for the positive feedback on the troubleshooting resources provided for visual learners. Hope you find the information helpful. Let me know if you have any questions!

  5. Eric Schmidt says:

    Are there any DIY troubleshooting techniques for common lawnmower starting issues?

    • Allard Vdhooft says:

      Yes, Eric, there are DIY troubleshooting techniques for common lawnmower starting issues. Check out the blog post for detailed solutions!

  6. Max Hicks says:

    What are some safety precautions to take while troubleshooting a lawnmower that won’t start?

    • Allard Vdhooft says:

      To troubleshoot a lawnmower that won’t start, check the spark plug, ignition system, carburetor, and filters. Address these issues before seeking professional help.

  7. Sofia Nelson says:

    Learning about the possible reasons behind a lawnmower shut down was eye-opening.

    • Allard Vdhooft says:

      Thank you, Sofia! I’m glad you found the information eye-opening. Let me know if you have any questions or need further assistance with your lawnmower.

  8. Allison Wright says:

    Are there any specific maintenance routines to prevent common lawnmower starting issues?

    • Allard Vdhooft says:

      Hi Allison, to prevent common lawnmower starting issues, ensure your spark plug, ignition system, carburetor, and filters are clean and functioning. Regular maintenance is key!

  9. Lucas Hart says:

    How can one differentiate between an electrical and a mechanical starting issue in a lawnmower?

    • Allard Vdhooft says:

      Lucas, to differentiate between an electrical and a mechanical starting issue in a lawnmower, first check the spark plug, ignition system, and carburetor for gas-powered models. For electric mowers, ensure the connections are secure and batteries charged.

  10. Beth Sanders says:

    How often should the spark plug be replaced in a lawnmower?

    • Allard Vdhooft says:

      Hi Beth, typically spark plugs should be replaced every 25 hours of engine use to ensure your lawnmower starts smoothly. Regular maintenance can help avoid starting issues in the long run.

  11. Bradley Bryant says:

    I didn’t know there were so many reasons why a lawnmower might fail to start.

    • Allard Vdhooft says:

      Bradley, I’m glad you found the information helpful! There are various reasons why a lawnmower may fail to start, and it’s essential to troubleshoot the issues step by step for a successful repair.

  12. Tanya Barrett says:

    Are there any specific maintenance tips for ensuring a lawnmower starts smoothly?

    • Allard Vdhooft says:

      Ensure the spark plug, ignition system, carburetor, and filters are clean and working correctly for smooth lawnmower startups. Additional tips are available on the blog post for troubleshooting.

  13. Jill Caldwell says:

    Do electric lawnmowers have fewer starting problems compared to gas-powered ones?

    • Allard Vdhooft says:

      For electric lawnmowers, starting problems are typically related to power sources, fuses, and switches. Gas-powered mowers often face ignition, fuel, and carburetor issues. Consult the blog post for detailed troubleshooting tips.

  14. Kylie Bryant says:

    Is it advisable to seek professional help if I’m unable to diagnose and fix my lawnmower’s starting problem?

    • Allard Vdhooft says:

      Seeking professional help is advisable when unable to diagnose and fix your lawnmower’s starting problem. It may involve complex issues that need expertise to resolve effectively.

  15. Owen Jackson says:

    Very informative and helpful tips on troubleshooting lawnmower starting problems.

    • Allard Vdhooft says:

      Thank you, Owen! I’m glad you found the troubleshooting tips helpful. Let me know if you have any questions or need further assistance.

  16. Marc Wood says:

    This article is quite comprehensive in addressing various types of lawnmower starting problems.

    • Allard Vdhooft says:

      Thank you, Marc! I’m glad you found the article helpful in addressing lawnmower starting problems. Let me know if you need further assistance or have any questions.

  17. Jeanne King says:

    Thank you for the detailed explanations and solutions for fixing lawnmower problems.

    • Allard Vdhooft says:

      Thank you, Jeanne! I’m glad you found the explanations helpful in fixing lawnmower issues. Happy mowing!

  18. Savannah Gibson says:

    I feel more confident in troubleshooting my lawnmower after reading this article.

    • Allard Vdhooft says:

      Thank you for your comment, Savannah! I’m glad the article helped you feel more confident in troubleshooting your lawnmower. Happy mowing!

  19. Aubree James says:

    What are some common signs of a bad spark plug in a lawnmower?

    • Allard Vdhooft says:

      Bad spark plug signs: difficult starting, engine misfires, poor fuel efficiency. If these symptoms appear, consider checking the spark plug for wear or damage.

  20. Emily Robertson says:

    I appreciate the detailed solutions provided for each type of lawnmower issue discussed.

    • Allard Vdhooft says:

      Thank you, Emily! I’m glad the solutions were helpful. If you have any more questions or need further assistance, feel free to ask. Happy mowing!

Comments are closed.