Before you start any gas mower maintenance, always disconnect the spark plug and, secure it off to the side so it won’t start accidentally.
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Wear heavy gloves to protect your hands. To prevent fuel from leaking when you tip the mower on its side, close the gas cap over a sandwich bag.
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3. REMOVE BLADE
A block of wood or a blade removal tool will keep the blade from moving as you loosen it. Free the lawn mower blade by unscrewing the bolts.
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4. SHARPEN BLADE
Your blade doesn’t need to be razor sharp, just free of nicks with a clean, smooth edge. If you don’t have a bench grinder, a rotary tool lawn mower sharpening attachment makes this quick work. It’s designed to put an accurate 30 degree angle on the blade.
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5. BALANCE BLADE
An unbalanced blade can vibrate and damage the engine. Check your blade before reinstalling using a blade balancing tool. Or, hang the blade on a nail. If it’s dipping to one side, sharpen from the back edge of the heavier side until it’s balanced.
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6. REPLACE BLADE
Use a torque wrench to replace the blade so you can tighten the bolt to the precise setting. Set the wrench to the correct “ft-lb” indicated in the owner’s manual. Over tightening the blade can damage the engine and prevent the blade from spinning freely. Under-tighten it and the blade could loosen and fall off.
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7. HELPFUL TIP
Gasoline gets stale in 4-6 weeks and can gum up the lawn mower’s carburetor. At the end of the season, run the mower to empty the tank, or add fuel stabilizer to the tank to winterize your mower.
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8. HELPFUL TIP
Use a fuel system revitalizer if stale fuel prevents your mower from starting.
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9. HELPFUL TIP
If you don’t want to sharpen the blade, just buy a replacement. Or, check your local Ace for sharpening services.