Lawn appliances, such as lawn mowers and string trimmers, have a primer bulb to send fuel to the carburetor for starting. Pressing the rubber or plastic bulb pulls fuel from the fuel tank and pressurizes it through the fuel line to the carburetor. Replace faulty primer bulbs with cracks in them to prevent gasoline from leaking on the machine and the possibility of a fire caused by fuel dripping on a hot engine.
Things You'll Need
- Small slotted screwdriver
- Small Phillips screwdriver
Place a pair of hemostats on the fuel line. Squeeze the handles together to cut off the flow of gasoline.
Pry both fuel lines off the primer bulb's back, using a small slotted screwdriver.
Grasp the tabs on each side of the primer bulb and squeeze them inward. Turn the bulb to align the tabs in the openings of the mounting ring. Pull the bulb straight out.
Remove the screws on the air cleaner cover, located on top of the air filter. Depending on the item and manufacturer, there will be two to four screws. Turn the screws loosen them, then pull them straight out.
Pull the air cleaner cover straight off the tool. Pull the air filter straight off. The carburetor choke plate is now visible.
Insert a screwdriver into each of the two carburetor mount screws. Turn each screw counterclockwise to loosen and remove them. Pull the carburetor choke plate straight off and set it aside. The primer bulb is on the bottom of the carburetor.
Unscrew the four screws surrounding the primer bulb on its mount, using a small Phillips screwdriver. Pull the top mounting plate off the bulb. Pull the bulb out of the bottom half of the mount.
Tips & Warnings
- Clean the primer bulb area with a shop cloth before installing a new bulb. Oil and debris usually surround the mounts.
- Place a shop towel underneath a carburetor-mount primer bulb to absorb the small amount of fuel that will leak from the bulb.
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