What should I check on my lawn mower?

Keeping your lawn mower in good working condition is crucial for maintaining a healthy, attractive lawn. Before each mowing session, it’s important to check several components on your mower to ensure it operates properly and safely. Here are the key things you should inspect on a regular basis.

Check the Engine Oil

One of the most important checks you should make is checking the oil level in the mower’s engine. An engine needs oil to lubricate moving parts and prevent overheating. Most mower engines hold between 12 to 48 ounces of oil, depending on the size and model. To check the oil:

1. Make sure the mower is on a flat, level surface and has not been tipped at an angle for at least 5 minutes. This allows the oil to settle into the crankcase.
2. Locate the oil fill cap/dipstick, remove it, and wipe it clean with a rag. Slowly thread the dipstick back into the fill tube but do not screw it in.
3. Pull the dipstick out again and check the oil level. It should be between the “Full” and “Add” markings on the dipstick. If it’s below the “Add” line, add more oil until it reads full.
4. Replace the dipstick securely when finished.

Be sure to use the type and grade of oil recommended by your mower’s manufacturer. This info is typically found in the owner’s manual. Checking the oil before each use can help prevent serious engine damage from running low on oil.

Inspect the Air Filter

The air filter is another vital component to check. This filter prevents dirt and debris from entering the engine’s cylinders. A clogged air filter can reduce engine performance and increase wear on parts. To inspect it:

1. Locate the air filter housing, usually on the side or top of the engine. Release any clamps or screws holding the housing cover in place.
2. Remove the foam or paper filter element and check for dirt buildup. Lightly tap it on a hard surface to remove loose debris.
3. If the filter is excessively dirty, replace it with a new one. Use care not to damage the filter when removing or installing it.
4. Replace the cover tightly once finished.

Check the condition of the air filter before each mowing and replace it as needed, approximately every 25 hours of runtime. Using an excessively dirty filter will hamper airflow to the engine.

Check the Blade

Keeping the mower blade sharp and properly balanced is crucial for clean cuts and engine efficiency. Inspect the blade for the following issues:

• Sharpness – A sharp blade cuts grass cleanly. A dull one tears and shreds the blades. Run your hand carefully across the cutting edge to check its sharpness.
• Nicks and dents – Inspect for dents and chips in the cutting edges and ends of the blade. Small imperfections can be filed out, but deeply damaged spots may require replacing the blade.
• Bending – Spin the blade by hand and watch the blade tips. They should pass close by with minimal wobble. If the blade is bent, it can damage the mower and needs replacement.
• Excessive wear – Measure the blade thickness near the cutting edges. If significantly thinner than a new blade, it’s worn out and should be swapped for a fresh one.
• Cracks – Carefully inspect the full length of the blade for any tiny cracks, especially near the central mounting area. Cracks compromise strength and call for a new blade.

Plan to replace mower blades after 25-50 hours of use, or more often if mowing on sandy soils. Keep extras on hand so dull and damaged blades can be swapped out promptly.

Inspect the Cutting Deck

The mower deck, or underside housing, should be checked prior to use. Watch for:

• Clogged areas – Buildup of grass clippings and debris under the deck can interfere with cutting quality. Clean out any clutter with a stiff brush.
• Damage – Look for dents, cracks, or holes where objects have made impact. Damage can lead to uneven cutting.
• Blade clearance – Blades should have about 1/4″ – 3/8″ of clearance from the deck bottom. Adjust if needed to prevent blade strikes.
• Belt wear – Inspect belts (if equipped) for deterioration, cracks, or fraying. Worn belts should be replaced promptly.

Keep the underside of the cutting deck clear of buildup. Promptly repair any damage that occurs.

Check the Gas Level

Running out of gas during mowing can not only be frustrating, it can damage the engine. Always check the fuel level before you start:

• Use the fuel gauge on the tank if equipped to check level.
• If no gauge, tip the mower carefully to inspect fuel at the tank opening or through a clear window.
• Refuel if gas level is under 1/4 tank.
• Use fresh, clean gasoline with an octane rating as recommended by the engine manufacturer.
• Avoid overfilling the tank which can cause spillage or damage.

Adding fuel stabilizer to the tank can help keep gasoline fresh longer when the mower isn’t in frequent use.

Check Tire Pressure

Consistent tire pressure is key for smooth handling and proper cut quality. Tires that are over- or under-inflated can lead to uneven cutting. Use a tire pressure gauge to check the pounds per square inch (PSI) in each tire. Add or release air as needed to match the recommended inflation molded into the tire sidewall. Proper inflation provides optimal traction and prevents tire and wheel damage.

Check Safety Features

Be sure to test any safety mechanisms before mowing:

• Blade brake clutch – The blade should stop spinning within 3-5 seconds of releasing the blade control.
• Operator presence controls – The engine should cut off if you release the blade clutch or shift out of gear without pulling the safety bail.
• Guards – Make sure discharge chutes and other protective guards are in place and in good condition.
• Headlights – Test headlight function if mowing at night to ensure clear visibility.
• Safety labels – Replace any safety decals that are faded, damaged, or missing.

Proper operation of safety mechanisms is critical to help avoid accidents and injuries.

Inspect Belts & Pulleys

If your mower has any belts and pulleys for the deck or drive system, check them over closely. Look for:

• Fraying, cracking, or damage in belts
• Belt tension – some slack is normal, but belts should be snug
• Pulley alignment – pulleys should be parallel and free of wobble
• Bearing wear in pulleys – wiggle pulleys to check for slop or grinding
• Belt routing – ensure belts are correctly routed conforming to any guides

Replace damaged, excessively worn, or loose belts promptly. Misrouted and loose belts can come off during use.

Check Wheels & Axles

The mower’s wheels take a lot of abuse from debris, curbs, and ground impacts. Inspect them for:

• Missing or loose lug nuts
• Cracked or bent wheels
• Axle and wheel bearing play
• Debris stuck in wheels
• Damaged tires and tread
• Misalignment

Tighten any loose hardware, remove stuck debris, and replace damaged wheels or tires as needed. Proper wheel condition allows smooth steering and operation.

Inspect Control Cables

Control cables connect the mower’s handles to components like the blade engagement lever. Check cables for:

• Fraying or broken strands
• Kinks and bends
• Damage to outer sheathing
• Proper adjustment – some slack is needed for full functionality
• Lubrication per manual instructions to prevent binding

Replace and lubricate damaged control cables to restore proper operation. Binding cables can prevent blade shutoff when needed.

Check the Battery

Mowers with electric start rely on a starter battery. For reliable starting, check:

• Battery charge level – should read full charge on a voltage meter
• Clean battery posts and cable clamps – remove corrosion
• Battery hold-down – ensure battery is properly secured
• Cracked battery case – indicates replacement is needed

Recharge or replace weak batteries. Loose connections lead to hard starting and drainage.

Listen to the Engine

Start up the mower’s engine and listen closely for any abnormal sounds like:

• Knocking or rattling – indicates internal engine issues
• Rubbing or scraping – could signal fan blade damage
• Excessive vibration – can mean blade imbalance or loose parts
• Whining or screeching – bearing wear, belt slippage, or alignment problems
• Backfiring – points to carburetor trouble

Investigate and correct any unusual noises right away to prevent bigger problems down the road.

Conclusion

Giving your mower a thorough pre-use inspection only takes 10-15 minutes but is crucial for continued safe and effective operation. Developing consistent maintenance habits can significantly extend the life of your mower and ensure a healthy lawn for years to come.