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Your Generac Pressure Washer is Leaking Gas: FIXED!

When your pressure washer is leaking gas or smells like gas, you must find and repair it before using it.

You may be lucky enough to find a wet area indicating where the leak is coming from or it may be difficult to find because the gas has already evaporated and only left the smell of gas in the air.

A Generac pressure washer may begin leaking gas from the carburetor due to a bad carburetor bowl gasket, or a stuck float or float needle. It may also begin leaking from the fuel filter, fuel lines, fuel shut-off valve, or fuel tank.

Always work in a well-ventilated area. Wear proper protection when working with the fuel system. Allow the pressure washer to cool.

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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.

5 Places a Generac Pressure Washer Can Begin Leaking Gas

1. Carburetor (3 places to look)

It is common for a leak to develop from the carburetor. This is the place where a little fuel is stored once it leaves the fuel tank.

Old fuel will leave behind varnish and deposits that can cause internal carburetor parts to not function correctly.

When looking for a leak on the carburetor, check for a bad carburetor bowl gasket, stuck float, or stuck float needle.

Gasket failure in the carburetor bowl

Begin by looking for a leak coming from the carburetor bowl. There is a thin gasket that is placed between the carburetor and bowl to create a seal. This gasket looks a lot like a thin rubber band.

It is common for this gasket to become hard and brittle over time. Because of its close proximity to the engine, the gasket heats up when the engine is running and cools down when it is not.

This constant heating and cooling put a lot of stress on the gasket causing it to lose its sealing ability. When you find a leak in this area, it’s time to purchase a new carburetor bowl gasket and install it.

Steps to replace the carburetor bowl gasket:

  • Shut off the fuel supply using the fuel shut-off valve if it uses one. You can also use pinch pliers to crimp the fuel line to stop the flow.
  • Wipe the outside of the carburetor so you don’t allow any dirt to enter the carburetor while removing the bowl.
  • Have a rag or small container available to collect any fuel remaining in the bowl.
  • The carburetor may have a screw located on the side of the bowl to empty the fuel bowl. If yours does, remove the screw, drain the fuel into a container, and replace the screw. If not, proceed with the next step.
  • Remove the screw from the carburetor bowl and remove the bowl.
  • Remove the old gasket and replace it with the new gasket.
  • Reinstall the carburetor bowl.
  • Reinstall the screw to hold the bowl and carburetor together.
  • Wipe down the carburetor again to remove any spilled fuel
  • Turn on the fuel supply and check for additional leaking from the carburetor.

Stuck float in the carburetor

Next, look for a fuel leak near the air intake port. When you find a leak in this area, you could have a stuck float that can no longer regulate fuel flow into the bowl.

Fuel keeps flowing into the carburetor bowl and then overflows out of the carburetor when you have a stuck float.

Take your carburetor apart when you find a stuck float to determine the actual cause of the failure. You may be able to clean the carburetor to keep the float from sticking.

You may also have to rebuild it to get the carburetor to work right or you may have to replace it with a new carburetor.

Stuck float needle in the carburetor

The last thing you should check on your carburetor is the float needle. The float needle works in conjunction with the float to keep gas flowing into the carburetor bowl. If the needle gets stuck, it will need to be repaired.

You will have to take your carburetor apart to fix the float or you can take it to your local small engine mechanic to have the carburetor rebuilt.

2. Bad Fuel Shut-Off Valve or Fuel Filter

Your Generac pressure washer may have a fuel shut-off valve or fuel filter component that attaches to the bottom of the fuel tank. This may be the spot where your pressure washer is leaking.

The part may be made of plastic or metal. Both types are prone to leaking and must be replaced when you find a leak.

The fuel shut-off valve may have a sediment bowl and seal. If it begins to leak around the bowl, remove the bowl and seal, clean the bowl, and install a new seal if available. Otherwise, replace the complete valve.

Replace a bad fuel shut-off valve or tank joint fuel filter.

3. Fuel Lines

Fuel lines will become dry and brittle with age. They will develop cracks over time where fuel will begin leaking. Any cracked fuel lines need to be replaced.

In addition to looking at the age and condition of the lines, make sure the hose is securely connected to the fuel components and the fuel isn’t seeping out of the connections.

4. Fuel Tank Failure

Your Generac pressure washer may have a metal fuel tank or a high-density polyethylene tank. Whichever kind you have, they can both develop leaks as they age.

The seams can fail on the polyethylene tank resulting in a fuel leak. Fuel sitting in a metal tank can cause it to corrode and form rust spots that may eventually develop a hole.

The best thing to do when you find a leak in the fuel tank is to replace it with a new one.

However, if you have a metal tank on an older model that is no longer being manufactured, you may not have this option. You can attempt to repair the hole.