How to Replace the Primer Bulb on a Briggs & Stratton 4.5

Briggs & Stratton lawnmowers have a primer bulb attached to the engine directly under the air filter. The primer bulb fills with fuel when pressed down, then releases this fuel into the carburetor. The carburetor is "primed" for starting. The fuel mixes with air during combustion and starts the engine. After several seasons of use, the primer bulb may dry out and then crack, causing fuel to spill out; this makes a proper prime impossible. Replacement of the primer bulb does not require the help of a professional mechanic.

Things You'll Need

• Screwdriver
• Primer bulb
• Socket wrench
• Hammer

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Instructions

1. • 1

     Remove the center screw from the air filter cover. Pull out the air filter.

   • 2

     Push in the tabs on the side of the primer bulb and pull out the bulb.

   • 3

     Place the new primer bulb over the hole.

   • 4

     Set a socket wrench that has a diameter slightly larger than the new primer bulb over the bulb. Tap the end of the socket wrench with a hammer to set the bulb in place.