Pressure Washer Shuts Off After a Few Minutes: Primary Causes

We’ve all been through the excitement of cleaning your car or patio, and when you start your pressure washer, it instantly revs up with that all-powerful purr you’ve gotten used to hearing. But after a few minutes, it shuts off. You start it again, only to have it die on you after a few moments.

If your pressure washer is shutting off after a few minutes, there is likely a fuel or air obstruction in one of these areas:

• Carburetor
• Fuel cap vent or fuel filter
• Air filter
• Spark arrestor

You will need to clean or replace one or more of these parts but the process is fairly straightforward.

Don’t stress over this. Let’s just work through it.

Clean or Replace the Carburetor

A clogged carburetor is most often the culprit if your pressure washer shuts off after a few minutes (source). As such, checking the carburetor should be the first thing you do.

How does a clogged carburetor happen? According to this Repair Clinic, when you leave fuel inside the tank of your pressure washer, some parts of it evaporate (source). This leaves a sticky and thick substance that can easily clog the carburetor.

If you have left your pressure washer in storage for quite some time and dies after a few minutes, cleaning the clogged carburetor will probably fix it. Here’s how you do that (source).

Tip: To make this process easier, take a photo before you disassemble anything.

1. Take off the spark plug cap and then turn the fuel valve off. Then locate the carburetor. You may need to take out the air filter box, the intake, and the throttle cover to gain access to the carburetor.

2. Disconnect the gas line that runs between the carburetor and the fuel tank. Empty the remaining old fuel from the carburetor. If you want to save the gas that you have just put into the tank, you can clamp down on the fuel line using a pair of pliers.

3. Remove the carburetor by taking out the bolts that connect it to the engine. Disconnect the throttle cable. Throw away whatever gas remains inside the carburetor into an old bowl or towel. 

4. Check if the carburetor is rusted. If it is corroded, you should buy a replacement (link to Amazon).

5. If your carburetor is dirty, you can clean it with ease by taking it apart and removing the carb bowl. Remove the pin that connects the metal body and the float and then pull out the needle valve.
   
   Use a carburetor cleaner like WD-40 Specialist or Gumout Jet Spray (links to Amazon). You should spray it on every metal part of the carburetor. Wipe everything dry.

6. Check to see if the main and idle jets are clear of any obstructions. You can use a small wire brush like this 10 Piece Brush Kit (link to Amazon) to clean these passages.

7. Rinse all the cleaned parts with water and then use compressed air to dry them all.

8. What else should you do? Clean other components with soap and water. Plus, check to see if there are torn or distorted gaskets and replace them.

9. Put all of these parts back to where they belong: Needle valve, floater, pin, gaskets, and carb bowl.

After all these, you can reconnect the carburetor to the engine and return everything to where they were.

Here’s a video that shows you exactly what to do:

Cleaning a small engine carburetor. Briggs and Stratton. Bad gas. Ethanol problems.

Further, you might need to buy a Carburetor Repair Kit (link to Amazon) for your pressure washer if cleaning it is not enough. This kit will allow you to replace certain parts of the carburetor that may need replacement and avoid replacing the entire carburetor altogether.

But the best way to deal with this problem is to avoid clogging the carburetor. Here are some ways:

• Use only fresh fuel.
• Use a fuel stabilizer, such as STA-BIL Storage Fuel Stabilizer (link to Amazon), which can keep your fuel fresh longer.

Check the Fuel Cap and Fuel Filter for Clogs

Another possible reason your pressure washer starts and stops after a few minutes is that the fuel cap vent or the fuel filter might be clogged.  

The fuel cap allows air into the fuel tank so that it can continue to deliver gas to the carburetor even as the fuel level gets lower. If the fuel cap vent is clogged, the air is blocked from entering the tank, and vapor lock will happen. 

Vapor lock will stop the flow of fuel, which may explain why the engine stalls and dies. How do you know if the fuel cap is the problem? Loosen it and start your pressure washer, if it starts and continues to run without any problems, then you will need to replace the fuel cap.

On the other hand, if the fuel filter is clogged, it will prevent the gas from getting into the carburetor. Like a carburetor, fuel filters get clogged when you leave fuel in the tank for a long time, and it gets sticky when some ingredients evaporate (source).

To fix this, you will need to replace the fuel filter. The process is pretty quick and easy:

1. You should shut off the fuel valve at the base of the fuel tank. If you don’t see a fuel valve, you can clamp the fuel line.

2. Filters may be installed in the fuel line itself, so you will need to remove the metal clips that attach the filters and slide it out of the fuel line.

Here’s a great visual walkthrough of the process courtesy from YouTube:

How to Change Your Mower's Fuel Filter

Change the Air Filter if It’s Dirty

Air filters help keep dust, debris, and dirt from entering the engine and the carburetor. As such, air filters can help you get more life from your pressure washer.

However, dirty air filters will restrict the air that comes into the carburetor and stall the engine. Air filters should be replaced once a year, or whenever you see that it has gotten dirty.

Here’s how you do it (source):

1. Remove the air filter cover and then pull out the foam filters from the assembly.

2. Wash the air filter with paint thinner, mineral spirits, or other solvents with a high flash point (source). Do not twist or tear the filter. To dry it, squeeze it gently.

3. Soak the filter in unused engine oil and then squeeze it gently.

4. If you need to replace the air filter, soak the new one in clean water first and then in engine oil.

5. Put the cleaned or new air filter back into place and close the cover.

Here’s a video that shows you what to do:

Pressure Washer Air Filter Cleaning

Clean the Spark Arrestor

A spark arrestor prevents your pressure washer’s engine from emitting sparks. But it may be clogged with soot as time goes by. You will need to remove the spark arrestor and clean it using a wire brush.

This video will show you how to access, remove, or replace the spark arrestor on your pressure washer:

Pressure Washer Spark Plug Change

Conclusion

Nothing can be more frustrating than a pressure washer that dies on you even before you get to start cleaning. Fortunately, it’s the carburetor that’s the culprit most of the time. If cleaning a clogged carburetor doesn’t work, you can also check the fuel cap, air filter, fuel filter, or the spark arrestor.

The fixes are easy and will not require you to have special tools. You also don’t need to call in a professional if one of these turn out to be the issue.

Related Reading:
Pressure Washer Stalls When the Trigger Is Released