Gas Walk-Behind Mower: Why does my lawn mower cut unevenly?

If your lawn mower isn't cutting the grass evenly, first make sure that the wheels are set at the same height. If a wheel is damaged, replace it to ensure that the mower travels evenly over the lawn.

Also check that the blade is sharp and undamaged. A dull blade tatters rather than slices the ends of the grass, leaving the tips brown and dry. A damaged blade is off balance, so it cuts unevenly. Replace the blade if it's damaged.

gas walk-behind mower

THESE REPAIRS MAY HELP SOLVE YOUR GAS WALK-BEHIND MOWER PROBLEM

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Replace a lawn mower blade

A dull or damaged blade won't cut grass evenly. For safety and for a cleaner cut, replace a mower blade that's chipped, broken or otherwise damaged. If the mower vibrates too much, check the mower blade for damage because a bent or unbalanced blade can cause mower vibrations.

Replace a lawn mower blade

Find the required part specific to your product.

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March 1, 2016By Lyle Weischwill

How to replace a lawn mower blade

When your lawn mower blade is no longer making the cut because it's dull, bent or damaged, follow the steps in this repair guide and video show how to replace the mower blade in about 15 minutes.

Repair difficulty
Time required
 15 minutes or less
JC-LM-Replace-a-lawn-mower-wheel

Replace a lawn mower wheel

The lawn mower won't move with a broken wheel. A damaged wheel can cause uneven grass cuts. If the wheel on a walk-behind mower is damaged, replace it with one that matches the size on the opposite side of the mower.

Replace a lawn mower wheel

Find the required part specific to your product.

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April 1, 2013By Lyle Weischwill

How to replace a lawn mower wheel

A worn or damaged lawn mower wheel can wobble. This step-by-step repair guide shows how to replace a lawn mower wheel in 5 quick steps.

Repair difficulty
Time required
 15 minutes or less

Symptoms for gas walk-behind mowers

Choose a symptom to see related walk-behind mower repairs.

Main causes: uneven wheel height settings, damaged wheel, dull or damaged cutting blade
Main causes: damaged cutting blade, loose cutting blade, damaged flywheel key, engine needs tune up
Main causes: dirty carburetor, bad spark plug, clogged air filter, engine choke problems, clogged gas cap vent
Main causes: engine needs tune up, dirty or clogged carburetor, damaged flywheel key
Main causes: drive control cable failure, worn or broken drive belt, bad transmission, broken drive wheel
Main causes: stale gas, engine needs tune up, bad spark plug, dead battery, bad recoil starter, faulty safety switch, bad ignition coil

Repair guides for gas walk-behind mowers

These step-by-step repair guides will help you safely fix what’s broken on your walk-behind lawn mower.

March 1, 2016
By Lyle Weischwill
How to replace a lawn mower blade

Check your lawn mower blade regularly and replaced it if it's bent or damaged.

Repair difficulty
Time required
 15 minutes or less
How to replace a lawn mower ignition coil on an OHV engine

Replace the ignition coil if it isn't sending electric current to the spark plug when you pull the recoil starter rope.

Repair difficulty
Time required
 30 minutes or less
How to replace a lawn mower flywheel key on a flathead engine

When you hit a hard object with your mower, the flywheel can shear to protect more expensive components. Learn how to replace this tiny but essential part.

Repair difficulty
Time required
 45 minutes or less

Articles and videos common to all walk-behind mowers

Use the advice and tips in these articles and videos to get the most out of your walk-behind lawn mower.

October 1, 2019

Types of walk-behind mower blades video

By Sears PartsDirect staff

Learn about the different kinds of mower blades and how to maintain them.