You smell gas coming from your generator, but you just can’t find where it’s coming from. If you don’t initially see signs of a gas leak, it may evaporate into the air making it increasingly hard to find a wet spot left behind by a leak.
A Generac generator may begin leaking 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. Protect your eyes when working with the fuel system. Follow all safety precautions listed in your Generac operator’s manual.
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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 Generator Can Begin Leaking Gas
Carburetor (3 places to look)
Your carburetor is a good place to start looking for a fuel leak. Fuel sitting in the carburetor creates varnish that can cause its small parts to stick so it no longer regulates the amount of fuel allowed to enter the carburetor.
In addition to internal components no longer working right, the carburetor bowl gasket can fail and cause a leak.
Carburetor bowl gasket failure
When looking for a leak on the carburetor, start by looking for a leak around the carburetor bowl. There is a thin gasket that looks a lot like a rubber band. Its purpose is to seal the carburetor bowl to the carburetor.
It is common for this gasket to become hard and brittle over time. 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 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 carburetor float
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
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.
Cracked or Soft Fuel Filter
Over time, gas can weaken the plastics used for the fuel filter. The filter can become soft and begin leaking at the seams. 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.
It’s important to run a good fuel filter on the generator. This is because it keeps dirt from getting to the engine which can cause wearing and permanent damage.
To keep the fuel filter from becoming soft, regularly replace it with a new one. I recommend replacing it annually and more often if you are using your generator often.
Fuel Tank Failure
Your Generac 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.
Faulty Shut-Off Valve
If your Generac generator has a fuel shut-off valve, it may be the spot your generator is leaking. Shut-off valves are prone to leaking and must be replaced when you find a leak.
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.