Why does my Gas Pressure Washer keep Shutting Off?

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By Kirsi Jansa

A gas pressure washer that keeps shutting off is a big annoyance while working. This guide explains why your gas pressure washer keeps shutting off.

10 Reasons a Gas Pressure Washer Keeps Shutting Off [Solutions Included] 

This guide covers the pressure washer shutting-off problem for the following brands

  • Karcher
  • Generac
  • DeWalt
  • Craftsman
  • Simpson
  • Wen
  • Blubery
  • Champion
  • Westinghouse
  • Honda

Important Read: How do you Fix a Gas Pressure Washer that won’t Start?

Carburetor Problems 

Unused fuel inside the carburetor starts to evaporate after a month, leaving a thick and sticky tar-like material in the carburetor. This substance blocks gas movement inside the carburetor, and your pressure washer keeps shutting off while working.

Learn more about fuel type in your gas pressure washer: What Kind of Gas does a Pressure Washer Use?

Solution: You can use a carburetor cleaner to remove the grime inside the carburetor. The cleaner dissolves the grime, and it is burnt along the fuel. The washer may stutter for a few minutes, but then it will run fine.

You may need to repair or replace the carburetor if the cleaner doesn’t work. The video below explains how you can clean a carburetor.

Clogs in the Fuel Lines 

Another common reason your gas pressure washer keeps shutting off is a blockage in the fuel system. A pressure washer’s fuel cap lets air inside to maintain gas flow to the carburetor. The vent can be blocked. The gas lines can be air-locked. It usually happens when the pressure washer runs out of gas.

A blocked fuel filter can also stop a pressure washer from running smoothly. The gas flow to the carburetor will be limited.

Solution: Check the air vent on the fuel cap is not blocked. You would need to remove air bubbles if the pressure washer ran out of gas. Do this by filling the tank with gas and tapping the gas bowl on the carburetor with a screwdriver. It will remove the bubbles.

A blocked fuel filter needs to be replaced. You may clean and reinstall the old one, but it is not recommended. Refer to your washer’s user manual for instructions to replace the fuel filter.

Check Spark Plug 

A faulty spark plug can also force your pressure washer to keep shutting off.

Solution: Remove the spark plug from the washer and inspect for any damages. Replace the spark plug if it is cracked, burned, or has carbon buildup.

Dirty Air Filter 

Air filters clean air that enters the engine and carburetor. Check if it is clogged with dust and debris.

Solution: You can clean a dusty air filter with compressed air and use it again. However, it is recommended to install a new filter if it is damaged.

Dirty Spark Arrestor 

The spark arrestor prevents the engine from emitting sparks. It can get blocked due to carbon buildup over time.

Solution: Remove the spark arrestor and clean it with a wire brush. You may need a professional to do this for you.

Ignition Coil 

A faulty ignition coil prevents the engine from starting as it provides the voltage surge needed to ignite the fuel.

Solution: Remove the ignition coil from the washer and use an ohmmeter to measure the resistance. You’ll have to replace the ignition coil, as repairing it is not a good idea.

Unloader Valve 

It releases pressure when the trigger is not engaged. A stuck unloader valve will cause the pressure washer to stall.

Solution: Remove the unloader valve from your washer. Check the user manual to see where it is located on your model. Clean the valve and put it back.

Kinks in Water Hose 

Pressure washers often stop running after 5-10 minutes because of a kink or blockage in the water pipes. The washer fails to get enough water and heats up.

Solution: Check that your pressure washer hoses don’t have any kinks or bends. Ensure that the water filter on the washer is free from debris restricting water flow.

Low Engine Oil Shut off 

Many brands, like Honda, have a low-engine oil-shut-off feature. The pressure washer starts normally, runs for a few seconds, and then dies.

Solution: Check that your washer has enough oil in it. It is critical to check oil levels before starting your washer. Replace the oil as recommended in the user manual.

Faulty Low Oil Sensor 

Why does the pressure washer keep shutting off after an oil change? The culprit is a faulty low-oil sensor.

Solution: You can kill the oil sensor to run your unit smoothly. Look for a small silver module near the stop switch. There will be a black wire leading behind the flywheel cover. Unplug the wire to eliminate the low oil shutdown sensor.

The pressure Washer Shuts off When Hot 

Reasons

  • Low oil
  • Kink in water pipes
  • Clogged carburetor
  • Blocked air filter

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