Pressure Washer Only Runs on Choke ( 4 Quick DIY Fixes )

Pressure Washer Only Runs on Choke

If your Pressure washer only runs on choke, then it means the carburetor is bad and could be a result of bad or old gas. You can easily fix this by either cleaning the carb Jets, checking air leaks, using the right gas, and also keeping the carburetor in the right condition.

If your pressure washer only runs on choke, then you’re actually risking your pressure washer engine which isn’t very good because it can get demands and could cost a lot to get it fixed.

However, you can fix your pressure washer only running on choke by following the 4 methods I will be writing about in this article.

So to know why your Pressure washer only runs on choke and how to actually fix it, you should consider reading this article till the end.

Reasons Your Pressure Washer Only Runs on Choke

Below are some of the reasons why your pressure washer only runs on choke and how to troubleshoot them.

Air Leak

The right amount of air in the gas is very necessary for an engine to work properly because if the air goes into the combustion chamber of the washer, it would affect how well the engine functions.

On the other hand, air leakage which could also be a result of bad fuel/air combination,  will delay the smooth running of the engine if it does not run on choke.

Using the Wrong or Bad Fuel

Another common reason why your pressure washer only runs on a choke is that you are either using the wrong fuel or a bad one.

Bad or wrong fuel can cause much damage to any engine, pressure washer also operates using an engine so it can also be affected by wrong fuel.

Every Engine has its specific fuel requirements and type. This is why it is important to check out which fuel is best for your engine and stick to using only it.

Fuel System Contamination

Fuel system contamination refers to the presence of unwanted substances or impurities in the fuel system of an engine.

When the fuel system becomes contaminated, it can cause various issues, including problems with engine performance and operation. One common symptom is when the engine only runs properly when the choke is on.

Here’s how fuel system contamination can lead to this behavior:

  1. Clogged Fuel Filter: The fuel filter’s primary function is to remove debris and impurities from the fuel before it reaches the engine. If the fuel filter becomes clogged with dirt, sediment, or other contaminants, it can restrict the fuel flow to the engine. This restricted flow of fuel may result in a lean fuel-air mixture, causing the engine to struggle to run smoothly. Engaging the choke can compensate for the lean mixture by restricting the air intake and enriching the fuel mixture.
  2. Dirty Carburetor or Fuel Injectors: If the carburetor (in older models) or fuel injectors (in newer models) become dirty or clogged with contaminants, they may not deliver the proper amount of fuel to the engine. This can lead to a lean fuel-air mixture, similar to a clogged fuel filter, causing the engine to run poorly. Again, using the choke can help create a richer mixture and improve engine operation.
  3. Stale Fuel: If the pressure washer has been sitting for an extended period with fuel in the tank, the fuel can become stale and deteriorate. Stale fuel may form deposits or varnish-like substances that can clog fuel lines, filters, and carburetor jets. These blockages can disrupt fuel flow and cause the engine to run poorly, necessitating the use of the choke to compensate for the lean fuel mixture

What is Choke?

According to Dictionary, a Choke is a valve in the carburetor of a petrol engine that is used to reduce the amount of air in the fuel mixture when the engine is started.

However, to better understand a choke, you should understand how it works, and below is a brief explanation.

When starting an engine, the choke valve plays a crucial role by limiting the amount of air entering the carburetor.

This feature proves especially useful when starting the engine in colder temperatures.

Due to the engine being cool, initiating its startup can be challenging. The choke valve assists by providing easier access to fuel, facilitating engine ignition.

The choke valve’s purpose is to enhance fuel availability for a smoother engine startup, but it should only remain engaged for a short period.

Experiencing engine stalling shortly after disengaging the choke valve indicates an underlying issue that needs attention.

It’s important to avoid running the engine with the choke engaged for more than five minutes. Extended use can lead to severe engine damage while also resulting in inefficient fuel consumption.

The video below explains everything you need to know about an engine choke and how it works

READ ALSOAre Simoniz Pressure Washers Any Good ?- All You Need to Know about Simoniz Pressure Washers

4 Quick DIY Fixes for Pressure Washer Only Runs on Choke – Troubleshoot Guides

Pressure Washer Only Runs on Choke

Here are some of the steps to take in other to fix a pressure washer that only runs on choke

Step 1. Work on Air Leakage

By now, you know that air leak also affects the flow of the pressure washer engine and allows it to only run on choke which is not good for any engine.

However, below are some simples steps to fix that

  1. Check the condition of the air filter: When the air filter is dirty, it can limit the airflow, leading to the engine relying on the choke and emitting more pollutants.
  2. Inspect the hoses and connections for leaks: Be sure to examine the hoses and fittings carefully, as any loose connections or damages can cause air to escape, affecting the engine’s performance.
  3. Evaluate the engine manifold for potential leaks: Check for any signs of leaks in the manifold, as these can allow air to exit and result in a lean fuel-air mixture, impacting the engine’s operation.
  4. Examine the exhaust system for possible leaks: If you suspect a leak in the exhaust system, it’s crucial to arrange an inspection promptly. Leaks can lead to the release of harmful emissions from the engine and pose a fire hazard.

Step 2. Fuel System Contamination

Here is a quick fix for fuel system contamination

  1. Inspect and clean the fuel filter: Remove the fuel filter and clean or replace it if necessary.
  2. Clean the carburetor or fuel injectors: Depending on the pressure washer model, clean the carburetor’s jets or the fuel injectors using an appropriate cleaner or by disassembling and manually cleaning the components.
  3. Drain and replace the fuel: If the fuel is stale, drain the old fuel from the tank and refill it with fresh fuel. It’s also a good practice to use fuel stabilizers or additives to prevent fuel degradation during periods of inactivity.

Step 3. Clean the Pilot jet 

If the pilot is dirty, fuel won’t easily pass through, that way, the engine won’t run properly. This is why it is very important to clean your pilot jet.

I have written an article that talks about the different methods to clean a pilot jet.

You can check it out and follow the steps to clean it and get your washer running smoothly and not on choke.

Step 4. Use the Right Fuel or Gas

By using the right fuel and ensuring its freshness, it will help the fuel flow and combustion, allowing the pressure washer to run smoothly without relying on the choke.

Here are some other things you need to know and do when it comes to fuelling

  1. Choose the correct fuel: Make sure to use the fuel recommended by the pressure washer manufacturer. Using the wrong fuel can cause engine problems.
  2. Use fresh fuel: Avoid using stale or old fuel. Over time, fuel can deteriorate and form deposits that clog the fuel system, leading to poor engine performance.
  3. Add fuel stabilizer: If the pressure washer will be unused for an extended period, consider using a fuel stabilizer. This additive helps prevent fuel degradation and keeps the fuel fresh.

How to Know the Correct Type of Gas For Your Pressure Washer

It is one thing to know that using the right fuel for your pressure washer will help fix and also prevent it from running only on choke, however, it is another thing to know the right and correct old to use.

The fuel you select for your pressure washer should meet specific requirements, but it doesn’t need to be different from the gas you use for your car.

To ensure optimal performance, consider the following guidelines:

  • Freshness: It’s important to use fresh gas that hasn’t been stored for more than 30 days. Stale fuel can negatively affect the engine’s operation.
  • Octane Rating and Ethanol Content: Use gas with an 87-octane rating, as specified by the manufacturer. Additionally, ensure that the fuel contains no more than 10% ethanol. This combination helps prevent engine damage and buildup.

By following these guidelines and using the correct gas, you can ensure that your pressure washer operates efficiently.

How To Tell If Gas Is Old

Just in case you are confused and want to know if the gas you got is old or then, below are a few things you need to look out for to easily identify old gas

Darker Coloring

One of the ways to identify an old gas is by its color. When gas is old, it becomes darker.

Naturally, Fresh gasoline is a yellowish color. As the gas becomes older, it tends to become darker and kind of brownish.

Thicker Texture

As the gas gets old, it becomes thicker. By becoming thicker, I mean that your gas would now have a gummy texture.

Sour Smell

When your gas becomes old, it will have a sour smell. By having a sour smell, I mean some sort of like a varnish.

If you notice an unusual odor in your gas that differs from the typical smell, it is likely an indication that the gas has gone bad or degraded.

Can you only run on a full choke?

No, it is not necessary to rely solely on a full choke. You can utilize a modified choke, which offers a slightly easier alternative to the full choke setting.

In the case of your pressure washer’s engine, severe flooding occurs when an excessive amount of fuel enters the combustion chamber.

READ ALSO: Fastest Fix for Pressure Washer Surging at Idle and Why Pressure Washer Surge at Idle

Troubleshooting Carburetor Problems

Here are some simple steps to take in other to troubleshoot a carburetor problem knowing that without a good carburetor, the washer and engine won’t work properly;

  1. Use clean fuel: Ensure the gas tank is filled with fresh, uncontaminated fuel. If you notice any slime or debris in the fuel, it’s advisable to filter or strain it before adding it to the tank.
  2. Check for cracks or leaks: Inspect the fuel line and carburetor fuel nook carefully for any signs of cracks or leaks. Also, examine the primer bulb for any cracks or damage that may affect its functionality.
  3. Clean or replace the air filter: Assess the air filter for dirt or debris accumulation. Clean the filter if possible, or replace it if it is excessively dirty or damaged.
  4. Clean and replace spark plugs: Keep the spark plugs clean and replace them if necessary. Dirty or faulty spark plugs can affect combustion and engine performance.
  5. Inspect the ignition coil: Scan the ignition coil for any signs of damage or flaws. If you notice any issues, consider replacing the ignition coil.
  6. Check the fuel pump: If the fuel pump is not functioning correctly, it can impact fuel delivery to the carburetor. If needed, replace the fuel pump to ensure proper fuel flow.
  7. Examine engine condensation: Check for any condensation buildup in the engine, as excessive moisture can affect the carburetor’s performance. Take appropriate steps to address condensation issues if present.

Keep the Carburetor in Good Condition

To ensure your pressure washer runs smoothly without relying on the choke, it’s essential to keep the carburetor in good condition.

Regular maintenance, such as cleaning or adjusting the carburetor, can help prevent fuel-related issues and ensure a proper fuel-to-air ratio for optimal engine performance.

Neglecting carburetor maintenance can lead to problems like clogged jets or air-fuel mixture imbalances, resulting in the engine running primarily on choke.

By prioritizing carburetor upkeep, you can enhance the overall functioning of your pressure washer.

FAQ on Pressure Washer Only Runs on Choke

Why does my engine only run with the choke on?

When the engine runs only with the choke on, it often indicates a fuel-related issue. It could be due to a clogged fuel filter, a dirty carburetor, or a problem with the fuel-air mixture. The choke restricts air intake, enriching the fuel mixture to compensate for the lean condition.

Why does my pressure washer run for 30 seconds then shut off?

If your pressure washer runs briefly and then shuts off, it could be caused by a fuel supply problem. Check for issues such as clogged fuel lines, a malfunctioning fuel pump, or a faulty carburetor. Insufficient fuel flow can cause the engine to stall after a short period of operation.

Do you start a pressure washer with the choke in or out?

The starting procedure for a pressure washer may vary depending on the specific model. However, as a general guideline, it is common to start the pressure washer with the choke in the closed position (on) to create a richer fuel mixture for easier starting. Once the engine warms up, the choke can be gradually opened (off) for normal operation.

Why does my pressure washer shut off when I release the trigger?

If your pressure washer shuts off when you release the trigger, it could indicate a problem with the unloader valve. The unloader valve diverts the water flow when the trigger is released, relieving pressure on the pump. A malfunctioning unloader valve can cause the engine to stall when the trigger is released.

Should the choke valve be open or closed?

The choke valve should be closed (on) when starting a cold engine. This restricts the air intake and increases the fuel-to-air ratio, making it easier to start the engine. Once the engine warms up, the choke valve should be gradually opened (off) to allow for normal operation.

Does a choke let air in?

No, a choke does not let air in. Its primary function is to restrict the air intake, reducing the amount of air entering the engine. This restriction increases the fuel concentration in the mixture, aiding in cold engine starting by creating a richer fuel-to-air ratio.


If your pressure washer only runs on choke, it means there is a problem with the carburetor or fuel. This could be due to using bad or old gas.

Running the engine solely on a choke is not good and can lead to engine damage, which can be expensive to fix.

However, there are ways to fix this issue. You can check for air leaks, use the right fuel, and address fuel system contamination.

It’s also important to keep the carburetor in good condition through regular maintenance.

By following these steps and taking care of the carburetor, you can ensure that your pressure washer runs smoothly without relying on the choke.