You are just mowing along as usual and your lawn mower will slowly lose power and then it will just shut off. This is not an instant shut down, it happens over a minute or so.
In many cases this is a simple fix and to test what the problem is, loosen the gas cap a little and if you hear air rushing in as you do, it probably means that your gas cap is not venting properly. A gas cap is supposed to let air into the gas tank but not let it escape.
Now start your lawn mower and see if it runs for a long time. If it does, you have a bad gas cap. If you still have the same problem, you need to check your fuel filter and down the line to the carburetor. Check the fuel filter by pinching off the fuel line and removing it from the carburetor. Then release the pinched hose and let it drain into a clear glass container. If the fuel doesn’t come out of the hose with any quantity, you most likely found the problem. If the flow is good, move onto the carburetor. It will need to be taken apart and cleaned of any debris or ethanol intrusion.
Still need help with your lawn mower? Visit our Locations page for a lawn mower repair shop near you.