The carburetor of your lawn mower engine mixes the fuel stored in the fuel tank with air so that it will combust. When starting a lawn mower, you will need to push a primer bulb three times to force fuel into the carburetor to get the process going. Primer bulbs do not require any maintenance, but over time, due to adverse weather conditions or improper storage, your primer bulb may become cracked or begin leaking. Replacing the primer bulb is the only solution.
Remove the air filter by unscrewing it so that the primer bulb is easily accessible.
Remove the plastic covering of the primer bulb and use the flat-head screwdriver to access the clip behind the primer bulb, which holds it in place. Turn the screwdriver slightly towards the primer bulb until it unclips. Repeat this step for the other clip.
Insert the new primer bulb into place, placing the new retaining clip around the bulb to hold it into place. Use the screwdriver to push the new retaining clip into place. Check to make sure it is secured tightly, then place the new plastic covering over the primer bulb.
Replace the air filter and test the primer bulb by pressing it three times and starting the engine. If you note any leaks, make sure that the retaining clip is in place.