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Pressure Washer Engine Not Starting, Causes and Fixes

Finally, the weather cleared up, and you want to clean your driveway or your car. However, your pressure washer doesn’t seem to start. If you aren’t familiar with the mechanical components and don’t exactly know where to troubleshoot from, then no need to panic since this article provides you with all the necessary steps and details that will surely make your pressure washer run again.

If a pressure washer does not start, the most probable cause is the absence of combustion in the engine, thereby not resulting in a successful power stroke. This problem may be linked to several reasons, and hence they need to be inspected individually.

Pressure washer engine not starting, what can it be:

  1. A Defective Spark plug not igniting the fuel
  2. The clogged carburetor in which restriction prevents the air-fuel mixture to be drawn in an appropriate amount
  3. Defective ignition coil not providing current to the spark plug
  4. Broken flywheel key that does not engage the crankshaft with the flywheel

Some additional causes include:

  1. Faulty fuel pump
  2. Excessive air trapped in the hose that exerts a significant backpressure

If you’re unsure how to troubleshoot the problem, we have broken down the steps in simple and user-friendly instructions.

Common Troubleshooting steps:

Most frequently, pressure washer engine solutions involve tuning and cleaning various components such as carburetor, filters, spark plugs, etc. We have listed the following troubleshooting steps that can certainly help resolve the problem.

1. Defective spark plug:

One of the most frequent causes of an engine not cranking is a defective spark plug. A spark plug serves an essential purpose of igniting the air-fuel mixture during combustion to keep your engine running. The plug consists of two leads that create an electric arc, which eventually produces the spark. Over time, carbon buildup can affect spark creation. Moreover, the electrode can also weaken due to wear and tear.

● Solutions:

– Inspection of the spark plug:

 Inspecting the plug for damage or wear and tear should help you check if the component is working or not. You should check if there is a considerable carbon buildup, or if any electrode is broken or not. You can find spark plugs here.

-Ignition tester:

To check if the plug is producing the spark, you can use an ignition tester. The tester’s terminals will show a strong spark indicating that the component is working correctly. No spark means that the plug is defective and must be replaced. You can find an ignition tester here.

– Replacing the plug:

You cannot repair a defective spark plug; hence a cheap solution can replace the component. As a general guideline, you should refurbish your spark plug every once a year.

You can find spark plugs here.

2. Clogged Carburetor:

Another most frequent cause of engine not cranking up is the clogging of the carburetor. A carburetor ensures that the air-fuel mixture in the appropriate proportion is supplied to the engine for combustion. When an engine does not start, the most probable reason is the absence of combustion taking place. In almost every case, a clogged carburetor is something that you should troubleshoot.

● Solution: Cleaning the carburetor:

To fix the carburetor problem, you should follow the steps below:

  1. Remove cover: Remove the front cover and air filter door of the pressure washer so that the carburetor becomes visible.
  2. Disconnect fuel lines: Carefully disconnect the fuel lines and remove the component from the main assembly. It would be best if you were cautious in removing the fuel lines so that no fuel leakage occurs.
  3. Disassemble the carburetor: After removing, you need to disassemble the carburetor. Carefully disassemble the screws and jets. It is recommended that you record a video during this procedure or take some photos of the assembly after every step so that you can assemble each part back onto its original place.
  4. Inspect jets: Now that you have removed the constituent jets and screws of the assembly, you should inspect them for dust particles and dirt that might have clogged their holes. This buildup is quite imminent since it occurs due to the dust particles that are a part of the air or fuel.
  5. Unclog with cleaner: To unclog the jets, a carburetor cleaner liquid can be used. You can also use compressed air for cleaning the holes and tubes.
  6. Reassemble: After the cleaning is finished, you can assemble the carburetor and fix it back onto its original place.

If you need to replace your carburetor, you can find Pressure Washer Carburetors here.

● Carburetor Preventative maintenance:

To enhance the lifetime of your pressure washer, and make sure the machine will start without problems, it is wise to do some preventive maintenance:

  • Fresh fuel: To ensure better performance and effectiveness of the carburetor, it is recommended that you should always use new gas for your pressure washer. Gas will go bad after a few months.
  • Fuel stabilizer: We also recommend that you add a fuel stabilizer in the fuel tank if you plan not to use it for some time so that its quality does not deteriorate. You can find Fuel Stabilizer here.
  • Carburetor repair kit: You can also purchase a carburetor repair kit to help you in servicing and replacing the defective parts. You can find Carburetor repair kits here.

3. Defective Ignition coil:

An ignition coil sends voltage signals to the spark plug so that it engages the spark during combustion. If combustion is not occurring in the engine and the spark plug is also working fine, you need to check out for a defective ignition coil.

● Solution: Ignition coil tester:

To troubleshoot the ignition coil, you can use an ignition tester. If the tester terminals show a spark while the engine is running, it means that the coil is working correctly. If no spark is seen from the tester, then your ignition coil is defective and should be changed.

You can find an ignition coil tester here.

4. Broken flywheel key:

A flywheel key is a machine component that connects the crankshaft of your pressure washer engine with the flywheel. If the pressure washer does not start, one thing you can check is the flywheel key. This is because as your engine gets old, the key might wear out due to continuous operation and will need to be replaced. The key might also break if your washer hits a hard object with an impact.

● Solution: Replacing the key

You simply need to replace the key by fitting in a new one with a hammer. Then restart the engine again to check if the problem remains or not.


1. Fuel Tank and pump:

If a gasoline-powered pressure washer does not start, you should check if there is sufficient fuel in the tank. A fuel pump is installed, which is a motor that carries the fuel to the carburetor. If the engine won’t start and the fuel is also adequate, you should check if the fuel pump motor is working or not.

– Solution: Replacing the fuel pump:

A new fuel pump motor needs to be installed to transport the fuel mix to the carburetor. You can find pressure washer fuel pumps here.

2. Excessive air:

Another cause of the engine not starting might be the buildup of too much air in the water hose. The air buildup produces a back pressure onto the pump that might make it difficult for the engine to start.

– Solution: Air Removal from the hose:

To remove the air buildup, open the hose’s valve so that the water flows through it. You will witness a very narrow stream of water flowing out with difficulty due to the airlock. Keep the water running so that with time, the locked air is eventually released. Now try to crank up the engine again. Hopefully, it will start this time.


1. Electric Pressure washer won’t start: what to do?

There are several troubleshooting steps that you can try while working with an electric pressure washer. They are listed below:

– AC Outlet not working:

Before searching for other possible reasons for failure, it is better to start right from the basics. Make sure that the AC outlet you’ve plugged your machine into is functional. You should fix the plug if it is not working, or you can either plug the device somewhere else.

– Broken power cord:

You need to check the power cord of your device for faults and disconnections. Check out for bends and other zones in the cable where the wire might be possibly damaged. You can fix this issue by some basic soldering if you have identified the problem. Otherwise, it would be best if you changed your power cord with a new cable.

– Faulty capacitor:

If your washer’s motor does not start, but it produces a low humming sound, then it indicates that your capacitor has stopped working. Since it does not store any charge now, no current is delivered to the motor due to which it does not start. The repair of these electrical parts is usually unnecessary since most of these components are inexpensive and are readily available. Therefore, replacements ought to be made in place of repairs.

2. How long can you continuously run a pressure washer?

A pressure washer should not be run for more than three to five minutes. The idle running time may vary for different models. The prime reason that a pressure washer must not be left running idle is that it results in overheating of the engine. This overheating must be avoided at all costs since it can be detrimental to the machine components’ life. Hence it is advisable to avoid leaving the engine running and shut it down if you just got a phone call in the middle of the operation.

3. Can you let a pressure washer idle?

It is generally recommended to avoid keeping your pressure washer running idle. As you pull your machine’s trigger, the engine starts, and the pump begins delivering water at high pressure through the hose.  If your machine is left running idle, i.e., no spraying of water, then this water keeps circulating within the pump under pressure. The circulated water eventually becomes hotter and hotter. Most pumps have a discharge valve, i.e., when the temperature reaches a certain degree, the hot water is released, and fresh cooler water is drawn into the pump. Nevertheless, the pump’s continuous operation with high-temperature conditions can soften the seals and O-rings of the pump and hoses. Eventually, they might wear and need to be replaced.

4. Does a pressure washer need water to start?

You will be able to start a pressure washer without water. However, for the long-lasting performance of the equipment, it is advisable not to do so. This is mainly because the water acts as a coolant for the engine components, and without its circulation, the pump parts such as the impeller blades and the housing may heat up. This might have adverse effects.

5. Why does a pressure washer stall?

Pressure washer stall may originate due to similar reasons such as pressure washer engine not starting. The most common causes include:

  • Dirt buildup in the carburetor
  • Dirty air filter
  • Faulty spark plug
  • Dusty fuel filter
  • Carbon buildup in spark arrestor screen

Final Remarks:

In a nutshell, we can predict that the engine shutdown problems are primarily linked to combustion failure in the engine. For combustion to successfully initiate, the air-fuel mixture must be drawn in the appropriate proportion, and there should not be any dust or dirt particles in the mixture. These particles can clog the carburetors and filters’ holes and jets, which eventually causes this problem. Better maintenance of the engine will ensure that these clogging issues are minimized. In addition to that, the fuel quality must be adequately regulated by making sure that fresh fuel is utilized and fuel stabilizers. Better maintenance of the machine always guarantees a longer service life.

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  1. Brandy Garza says:

    What should I do if I can’t find the issue even after troubleshooting all the components mentioned?

    • Allard Vdhooft says:

      Hi Brandy, if you’ve exhausted troubleshooting options and still can’t find the issue with your pressure washer, consider getting professional help. Sometimes, complex issues require expert diagnosis.

  2. Tristan Fowler says:

    Thank you for breaking down the troubleshooting steps in such simple terms. Very helpful for someone like me with little knowledge about mechanical components. Great article!

    • Allard Vdhooft says:

      Thank you for your kind words! I’m glad the troubleshooting steps were helpful to you. Don’t hesitate to reach out if you have any more questions.

  3. Gavin Sanchez says:

    What if I don’t know how to do basic maintenance on my pressure washer?

    • Allard Vdhooft says:

      If you’re unsure about basic maintenance for your pressure washer, follow the troubleshooting steps provided in the article. They are user-friendly and will help resolve common issues. Hope this helps!

  4. Colleen Lewis says:

    I had no idea that a spark plug could be the reason my pressure washer won’t start, thanks for the insight.

    • Allard Vdhooft says:

      Thank you for reading! I’m glad the information was helpful. Best of luck getting your pressure washer up and running again!

  5. Marilyn Murray says:

    Is it necessary to replace the ignition coil if it’s defective, or can it be repaired?

    • Allard Vdhooft says:

      It is usually best to replace a defective ignition coil rather than repairing it. Trying to repair it may not provide a long-term solution and could result in further issues down the line.

  6. Shannon Rose says:

    What are the signs that indicate a faulty fuel pump in a pressure washer?

    • Allard Vdhooft says:

      If your pressure washer is not starting, a faulty fuel pump could be the cause. Make sure to check the fuel pump motor to ensure it is working properly. Hope this helps!

  7. Harvey Ray says:

    Can I replace the broken flywheel key myself, or do I need professional help?

    • Allard Vdhooft says:

      It is recommended to seek professional help when replacing a broken flywheel key to ensure correct installation. Working with small engine components can be tricky without proper experience.

  8. Bernard Harris says:

    This article has given me the confidence to try fixing my pressure washer myself.

    • Allard Vdhooft says:

      I’m glad the article gave you the confidence to try fixing your pressure washer! Remember to follow the troubleshooting steps carefully. Good luck with the repair!

  9. Terry Hall says:

    I never knew cleaning a carburetor could be so easy, thanks for the tips!

    • Allard Vdhooft says:

      Glad the tips helped, Terry! Let me know if you have any more questions. Happy cleaning!

  10. Rose Jacobs says:

    How can I prevent excessive air from building up in the water hose of my pressure washer?

    • Allard Vdhooft says:

      To prevent excessive air in your pressure washer hose, simply open the valve to release the airlock before starting the engine. This should help reduce back pressure and allow the engine to start smoothly.

  11. Joy Shelton says:

    The videos included in the article are a great visual guide for troubleshooting.

    • Allard Vdhooft says:

      Thank you for your positive feedback, Joy. I’m glad the videos were helpful in troubleshooting your pressure washer. Let me know if you need any further assistance.

  12. Christina Simmmons says:

    This article is a lifesaver for someone like me who has no knowledge about pressure washers.

    • Allard Vdhooft says:

      Thank you for your kind words, Christina! I’m glad the article was helpful to you. If you ever have any more questions or need further assistance, feel free to reach out. Happy cleaning!

  13. Leon Davis says:

    Is there a way to prevent these issues from happening in the first place?

    • Allard Vdhooft says:

      Thank you for your comment, Leon. The blog post provides detailed troubleshooting steps to prevent pressure washer issues from happening in the first place. Hope you find it helpful.

  14. Terra Russell says:

    How can I tell if the spark plug is defective just by looking at it?

    • Allard Vdhooft says:

      Inspect the spark plug for damage or wear. An ignition tester can help determine if it’s working. If no spark, replace the plug. Regular maintenance is key.

  15. Leah Russell says:

    Thank you for breaking down the complex mechanical issues into simple solutions.

    • Allard Vdhooft says:

      Leah Russell, thank you for your kind words. I’m glad the solutions provided were helpful to you in troubleshooting your pressure washer issues. Happy cleaning!

  16. Lois James says:

    The preventative maintenance tips are very useful, I’ll make sure to follow them regularly.

    • Allard Vdhooft says:

      Thank you, Lois! I’m glad you found the preventative maintenance tips useful. Following them regularly will surely help keep your pressure washer running smoothly. Let me know if you have any other questions.

  17. Jessie Simmons says:

    I appreciate the detailed explanations for each component and troubleshooting step.

    • Allard Vdhooft says:

      Thank you for your kind words, Jessie! I’m glad you found the troubleshooting steps helpful. Let me know if you have any other questions.

  18. Anne Fletcher says:

    Can I use any type of carburetor cleaner to clean my pressure washer carburetor?

    • Allard Vdhooft says:

      Hi Anne, it is recommended to use a carburetor cleaner specifically designed for pressure washer carburetors to ensure proper cleaning without causing damage. Hope this helps!

  19. Flenn Mitchell says:

    The troubleshooting steps provided are clear and easy to understand, great job!

    • Allard Vdhooft says:

      Thank you for your positive feedback, Flenn! I’m glad you found the troubleshooting steps easy to follow. Let me know if you have any other questions or need further assistance.

  20. Greg Anderson says:

    How often should preventative maintenance be done on a pressure washer?

    • Allard Vdhooft says:

      Maintenance should be done every 50 hours or yearly for a pressure washer, but check your manual for specific recommendations. Make sure spark plugs, carburetors, and ignition coils are inspected regularly.

  21. Richard Caldwell says:

    Great step-by-step instructions provided in the article, very helpful!

    • Allard Vdhooft says:

      Thank you for the positive feedback, Richard! I’m glad you found the instructions helpful. If you have any other questions or need further assistance, feel free to reach out.