Many lawnmower brands incorporate the Briggs & Stratton 6.5 HP engine.

How to Change the Air Filter in a Briggs & Stratton 6.5 Lawn Mower

by Chris Deziel

Briggs & Stratton doesn't make lawnmowers. Instead, the company manufactures the small engines that power them, and the 6.5 horsepower engine is one of the most popular. It's a two-stroke engine with one spark plug that powers a single piston to operate the mower blade. The carburetor is the heart of the engine -- it's the place where the fuel mixes with the right amount of air for combustion. To ensure the air passage is always open, the engine has an air filter you have to replace regularly as part of normal maintenance.

Unscrew the air filter cover on the side of the engine with a 5/16-inch nut driver. The cover is rectangular and black, and it has slots to admit air. If the screw head has a slots for it, you can also use a No. 2 Phillips screwdriver.

Pull the top of the cover back and unhook the tabs on the bottom from the engine to remove it. The filter will come with it. Take the filter out of the cover.

Put a new filter in the cover, hook the bottom tabs onto of the cover onto the engine and close it. Drive the screw to hold it.

Items you will need

  • 5/16-inch nut driver
  • No. 2 Phillips screwdriver


  • If the old filter is only slightly soiled, you may be able to reuse it. Clean it with compressed air, and if the pleats are then free of dust, put it back in the lawnmower.
  • Among the lawnmower brands using the Briggs & Stratton 6.5 HP engine are Sears Craftsman, MTD Yard Machine and Troy Bilt.


  • Change the filter before you use the lawnmower to avoid burning your fingers on hot engine parts.
  • Always make sure the lawnmower is off before you start working on it.

About the Author

Chris Deziel has a bachelor's degree in physics and a master's degree in humanities. Besides having an abiding interest in popular science, Deziel has been active in the building and home design trades since 1975. As a landscape builder, he helped establish two gardening companies.

Photo Credits

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