Gather your materials:
Engine degreaser
Carburetor cleaner
Wire brush
Old rags or towels
Safety glasses
Prepare the lawn mower:
Turn off the engine and allow it to cool down.
Disconnect the spark plug wire.
Remove the air filter.
Remove the carburetor bowl.
Apply engine degreaser:
Spray engine degreaser liberally into the combustion chamber.
Let the degreaser sit for the amount of time specified on the product label.
Scrub the combustion chamber:
Use a wire brush to scrub the inside of the combustion chamber, removing any carbon deposits or oil buildup.
Pay special attention to the piston head, valves, and spark plug area.
Rinse with carburetor cleaner:
Spray carburetor cleaner into the combustion chamber to rinse away the degreaser and any loose debris.
Remove any excess cleaner:
Use old rags or towels to wipe away any excess cleaner or debris.
Reassemble the lawn mower:
Reinstall the carburetor bowl, air filter, and spark plug wire.
Reconnect the battery if it was disconnected.
Start the lawn mower and let it run for a few minutes to circulate the new oil.
Note: Removing oil from the lawn mower combustion chamber is a messy job, so be prepared to get dirty. Wear safety glasses to protect your eyes from any flying debris.
