Pressure Washer Won't Start After Running Out Of Gas

Running out of gas is a common occurrence, in my workshop I hear customers describe this exact issue a lot. You are in the right place, a few minutes from now you'll be back washing.

A power washer that won’t start after running out of gas likely suffers from an air locked fuel system or dirt in the carburetor. Draining the gas bowl very often fixes the issue.  

In this post you'll learn why your washer won't start after running out of gas, you'll also learn how to drain the gas bowl and how to clean the bowl.

air locked fuel system

While an air locked fuel system isn't hugely common it can happen when a pressure washer runs out of gas. Air locking occurs when, as its name suggests, a bubble of air prevents gas making it's way to the carburetor.

The bubble of trapped air usually happens inside the small gas line between the gas tank and carburetor. 

Partially filling the gas tank after running out of gas will increase the chances of air locking. It's best to fill a gas tank as the weight of the volume of gas helps push trapped air to the carburetor where it's expelled.

Removing the air lock

The fix is simple follow these steps:

  • Fill gas tank to capacity
  • Leave gas cap off
  • Use a plastic handle screwdriver to tap on the gas bowl
  • Wait a moment and attempt to start the engine
Power washer gas cap off

Remove gas cap

Tapping screwdriver on carb bowl

Tap on gas bowl

For most, this simple procedure is all that's required to remove the trapped air. If however that isn't the case, draining the gas bowl will release the air. I cover that exact procedure below in gas bowl cleaning.

Dirty Power washer carburetor

Carburetors are finely tuned components which are tasked with supplying your power washer engine with the optimum volume of gas for engine load. 

It manages this process very precisely by employing small passage ways and ports in which gas flows. Even a tiny blockage is enough to cause a no start.

Dirt enters the fuel system usually at refueling, small particles of grit eventually make their way to the carburetor. The gas bowl is a reservoir of fuel at the base of the carburetor.

Spraying carb cleaner into carburetor emulsion tube

Any dirt in the fuel system will collect in the gas bowl. The bowl also houses the gas feed, which may be referred to as an emulsion tube or jet. It's a syphon that feeds gas to the engine.

It's easy to image how a a particle of grit could block the syphon process. 

Next we'll look at how we can remove the dirt, the easy way.

Diagnosis & repair

In many cases just draining the gas bowl is enough to release the dirt. However, bowl removal may also be required and if that doesn't fix the issue we'll need to remove, strip, clean and refit the carburetor.

But hey, lets think positive, lets just try draining the gas bowl first and see how that goes. 

Removing gas bowl drain bolt

Remove drain bolt

Draining power washer gas bowl
 

Draining carburetor gas bowl

Here we'll drain the gas bowl and test start the engine. The tools you'll need include a wrench set and some old cloths. As we'll be working with raw gas, it's best to work out doors, away from sources of ignition. You'll also need gloves and eye protection.

Note: Not all gas bowls have a drain bolt, and so if yours hasn't then go ahead and see cleaning gas bowl below.

Follow these steps to drain the carburetor gas bowl:

  • Turn gas tap off
  • Locate the carburetor bowl
  • Locate carburetor bowl drain (if fitted)
  • Place old cloths under the drain
  • Remove the drain
  • Refit drain after the bowl empties
  • Turn gas back on & test start the engine

If that worked out for you, fantastic! If it didn't we'll need to move to DEFCON 2 - cleaning the gas bowl. See below.

Gas bowl fastener location

Remove bowl fastener

Gas bowl
 

Cleanng carburetor gas bowl

Same tools, safety kit and precautions are needed here as they were in bowl draining. In addition, a can of carburetor cleaner would be useful. You'll find all the tools to nail this repair here on the "Pressure washer maintenance tools page".

Note: Old gas bowl seals often leak after being disturbed, if your bowl develops a leak after refitting the bowl, go ahead and replace the gas bowl seal and fastener gasket.

Remove and clean the gas bowl as follows:

  • Turn gas off
  • Place cloths under the gas bowl
  • Remove the bowl fastener
  • Remove the bowl, inspect & clean
  • Use the carburetor cleaner straw to spray the jet / emulsion tube
  • Refit the bowl taking care to seat the gasket correctly
  • Test and evaluate

For the great majority I'd expect this has nailed the problem, however if you're still not power washing, we'll need to remove and clean the carburetor.

Cleaning carburetor idle jet

Carb cleaning

Clean the carburetor

All carburetors need to be cleaned, you will notice the difference afterwards. Some carburetors are easier to work on than others, power washers tend to be pretty easy though. 

As this is a common issue, I covered it previously in this post "Lawn mower carburetor cleaning". The post covers a mower carburetor, but honestly the process is identical, all these engines are very similar.

For parts and tools, check out "Power washer  maintenance tools".

You may also find "Pressure washer troubleshooting page" useful.

Other posts you may find helpful:

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Auto Technician and Writer at Lawnmowerfixed | Website

John Cunningham is an Automotive Technician and writer on Lawnmowerfixed.com. I've been a mechanic for over twenty years, I use my knowledge and experience to write "How to" articles that help fellow gear-heads with all aspects of mechanical repairs, from lawn mowers to classic cars.