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Lawn Mower Leaking Gas

The lawn mowersmall engine often has a separate model number. Use the small engine model number for a complete list of symptoms and parts. Watch our model # lookup video for help finding the model number.

The part(s) or condition(s) listed below for the symptom Lawn mower leaking gas are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.

Most Frequent Causes for Lawn mower leaking gas

For the most accurate results, enter your model number.


Cause 1Carburetor Bowl Gasket

If the lawn mower leaks gas the carburetor bowl gasket on the bottom of the carburetor might be dried out or missing. If the leak is coming from the bottom of the carburetor, try replacing the carburetor bowl gasket.

Parts
Cause 2Float Needle

The float needle might not be shutting off the fuel. The float needle opens and closes the float valve to allow fuel to enter the float bowl. If the float needle is damaged, the carburetor will continue to fill with fuel until it overflows. If the float needle is defective, replace it.

Parts
Cause 3Carburetor Gasket

If fuel is leaking from the bottom of the carburetor, the carburetor gasket might be dried out or missing.

Parts
Cause 4Primer Bulb

Over time, the rubber of the primer bulb can become brittle and cracked. If the primer bulb is leaking, replace it. Don't try to patch or repair it.

Parts
Cause 5Fuel Shut-Off Solenoid

Check the fuel shut-off valve for leaks, and ensure that the fuel lines fit tightly on the valve. If the fuel shut-off solenoid is leaking, replace it. In addition, inspect the fuel shut off lines for cracks or tiny holes. If a fuel shut-off line is leaking, replace it.

Parts
Cause 6Float

The float might be stuck open. If the float is stuck open, remove the carburetor assembly from the engine and clean it thoroughly. If the cleaning the carburetor is not effective, either rebuild or replace the carburetor.

Parts
Cause 7Float Bowl

If fuel is leaking from the bottom of the carburetor, the float bowl gasket might be dried out or missing.

Parts
Cause 8Carburetor Repair Kit

If the engine carburetor leaks gas, rebuild the carburetor with this carburetor kit. Carburetor leaks can be caused by bad gaskets, an sticking float and other defects.

Parts
Cause 9Float Bowl Gasket

If fuel is leaking from the bottom of the carburetor, the float bowl gasket might be dried out or missing.

Parts
Cause 10Fuel Filter

Check the connections to the fuel filter and to the filter housing. If any of the fuel lines are dry or cracked, replace them. Don't try to cut off a piece of the fuel line and then reattach it.

Parts
Cause 11Fuel Line

If any of the fuel lines are dry or cracked, replace them. Don't try to cut off a piece of the fuel line and then reattach it.

Parts
Cause 12Fuel Pump

Ensure that the fuel lines and vacuum line fit tightly on the fuel pump. Inspect the fuel pump body for cracks or tiny holes. If the fuel pump has a leak, replace it.

Parts
Cause 13Fuel Shut-Off

The fuel shut-off valve might be leaking. Check the fuel shut-off valve for leaks, and ensure that the fuel lines fit tightly on the valve. If the fuel shut-off valve is leaking, replace it. In addition, inspect the fuel shut off lines for cracks or tiny holes. If a fuel shut-off line is leaking, replace it.

Parts
Cause 14Fuel Pump Body

Ensure that the fuel lines and vacuum line fit tightly on the fuel pump. Inspect the fuel pump body for cracks or tiny holes. If the fuel pump has a leak, replace it.

Parts