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Briggs & Stratton Generator is Leaking Gas (FIND & FIX)

You may begin smelling gas coming from your generator. Sometimes you will see a puddle of gas on the ground that may indicate the general area of the leak and other times you won’t be able to find it easily because the fuel has already evaporated.

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

Always work in a well-ventilated area. Allow the generator to cool for several minutes and take caution working around a hot engine.

Briggs & Stratton generator

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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 Briggs & Stratton Generator Can Begin Leaking Gas

1. Carburetor

The carburetor stores a little gas in the bowl after it leaves the fuel tank. Carburetors are subject to leaking from between the carburetor and the carburetor bowl.

It can also begin leaking when old gas causes internal parts to stick so the amount of fuel flowing into the carburetor is no longer controlled.

Gasket failure in the carburetor bowl

First look for a leak from the area between the carburetor and the carburetor bowl. There is a thin gasket that is used to create a seal between these two items. The gasket looks a lot like a rubber band.

It is common for this gasket to become hard and brittle over time. That is because it is located close 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 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 tank. 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

If you don’t find a leak around the carburetor bowl or you replaced the gasket and still have a carburetor leak, next look for a leak near the air intake port.

A leak in this area may be due to a stuck float. A stuck float won’t be able to regulate the amount of fuel flowing into the bowl and may overflow coming out of the carburetor.

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.

If you can’t get it cleaned or it is damaged, check to see if a rebuild kit is available to repair the carburetor. You may have to replace the carburetor with a new one.

Stuck float needle in the carburetor

You should also check the float needle in your Briggs & Stratton carburetor. 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. Cracked or Soft Fuel Filter

Fuel can weaken the plastic of your fuel filter causing gas to leak from the seams on the filter. If your model Briggs & Stratton uses a plastic inline fuel filter, check its condition.

When you find your filter leaking due to a crack or soft plastic you must replace it with a new one.

Be careful when removing the ends of the inline filter from your fuel lines. The plastic can become soft and break off. Install a new filter with the arrow located on the new filter pointed in the direction of the fuel flow.

To keep the fuel filter from becoming soft, replace the filter annually with a new one.

3. Fuel Tank Failure

Your Briggs & Stratton generator 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.

4. Faulty Shut-Off Valve

The fuel shut-off valve on a Briggs & Stratton generator is prone to leaking over time. This is true of both plastic and metal valves. When you find a leak from the valve, it should be replaced.

Some fuel shut-off valves have a sediment bowl attached. A seal is used to seal the bowl to the valve. 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.

5. 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.