When using your lawn mower, you may inadvertently run over a hidden sharp object like a screw or nail. This can puncture a tire and may cause a flat. Rather than replace the tire, use a tire plug kit to plug the leak. Tire plug kits are inexpensive and are available at any automotive store. All the tools to install the plug into the tire come with the kit.
Grasp the object that punctured the tire with pliers and slowly pull it out, if necessary.
Place two to three drops of rubber cement from the kit on the probe tool that came with the kit and push it into the puncture hole. Twist the probe and push it in and out of the hole several times to prepare the puncture hole. It will also enlarge the hole to the correct diameter so that you can insert the plug.
Thread the rubber plug through the needle tool. Position it so the needle is in the exact center of the rubber plug.
Add two to three drops of rubber cement to the needle's end and push it into the puncture hole. Continue to push it in until 1/4 inch is left outside the hole.
Give the needle tool a quarter turn in either direction and pull it out of the puncture hole. The needle tool should come out while the rubber plug remains in the hole.
Cut the plug down to just above the surface of the tire, using scissors. You should have about 1/8 inch of plug material sticking out of the puncture hole.
Fill the tire up to the recommended PSI, using your air compressor. The PSI is listed on the side of the tire.