How to Get Your Lawn Mower Ready for Spring

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If the relatively mild weather much of the country has seen this winter continues through this month, many homeowners may find their lawns waking up earlier than usual. So this might be a prime time to get your lawn tractor or lawn mower ready so that it will start when you need it.

If you have an electric mower, there's nothing to do beyond sharpening the blade and charging the battery (or batteries). A gas mower, particularly one that wasn't winterized, will need a bit of TLC before its first run of the season. Here are the steps to follow to get your gear in shape.

Change or Check the Oil

After a season of idleness, your mower needs to have its engine oil refreshed. Consult your owner's manual to see whether it prescribes changing the oil completely or just topping it off. 

Makers of several walk-behind mowers now say that you don't need to change the oil, just to add to it. If your manual says your model falls into that category, merely check the engine oil level with a dipstick and add oil as necessary. But don’t use the mower before then. A mower engine can overheat and fail prematurely from insufficient oil. "Running it for a few minutes is unlikely to cause damage," says John Galeotafiore, who heads CR's home improvement testing team. "It could lead to problems, though, if you use it to cut for an hour or so."

With other models, you'll need to change the engine oil entirely. Follow the manufacturer's instructions on emptying oil and adding anew. Typically, you can position an auto-style drain pan beside the mower on the side of the dipstick cap, remove the cap, and tip the mower over the pan to drain the oil. Then refill the tank with new oil to the dipstick marking. 

A tractor needs an oil change only as specified in your manual.

Galeotafiore mentions, by the way, that it's best to change the oil before addressing your mower's fuel situation. "There's less chance of spilling gas when you tip the mower over to drain the oil," he notes.

Fuel Up

Before you start up your mower, take steps to make sure that it has fresh fuel. A mower carrying leftover fuel—gasoline from last season that was never winterized with stabilizer, for instance—shouldn't be started up right away. Circulating stale fuel could create problems that require you to drain the lines.

Rather, remove that old gas from the tank using a turkey baster dedicated to the task. Then fill the tank with fresh fuel and stabilizer. 

If the tank holds gas that you winterized last fall, you don't have to do anything special. Assuming there's sufficient fuel, your mower should start right up.

And if you ran the mower dry last fall, you can add stabilized gas to the tank now.

Sharpen the Blades

Dull blades rip rather than slice grass, and that makes your mower work harder than it needs to. You can remove blades yourself and take them to a hardware store or other retailer that sells outdoor equipment for sharpening. The service should cost you about $10. 

To remove your mower’s blades, wear heavy leather gloves, remove the spark plug wire, and jam in a short 2x4 to keep the blade from turning as you loosen the bolts. Even tractor blades should be sharpened three times a year. 

If you have a battery mower, remove the battery before removing and sharpening the blade or blades. And on battery-powered tractors where you can't remove the battery, remove the key first and then remove and sharpen the blades.

Mind the Electrical

Your spark plug needs changing about every 100 hours of operation; if not, it can affect engine startup and overall performance. If you don’t know when you last changed it, do it before using the mower.

With the mower off, remove the spark-plug cap and use a socket wrench with a spark-plug socket to remove the old plug. Take it to an auto-parts store or outdoor-gear dealer and get a new one. For a tractor, most manuals instruct you to keep the battery indoors on a trickle charger. If you didn't, fully recharge the battery before starting the season or you’ll reduce battery life. The engine alone can’t fully recharge the battery. 

With a battery mower, there are no spark plugs, but you'll need to charge the battery(ies). 

Change or Clean Filters

A dusty air filter won’t prevent your gas-powered mower or tractor from starting, but a clean one makes your engine run efficiently. On a mower, it’s typically a pleated paper and can be removed in seconds. Take the old one to a lawn mower dealer or home center if you're not sure which one to get. If you know the mower model, it's just as easy to order a new air filter online.

For a tractor, replace your carburetor’s air filter if it’s paper. If it’s foam, wash it in soap and water. Rinse and squeeze it dry. Some manuals suggest you also oil a foam filter with engine oil. If so, squeeze the filter dry again before you reinstall it.

Tractors have a fuel filter, too. Check your manual for the proper maintenance schedule and procedure. 

Shopping for a New Lawn Mower?

Our lawn mower ratings include results of our tests of walk-behind mowers, lawn tractors, and zero-turn-radius riders. Before you go shopping, consult our lawn mower buying guide for advice on getting the right mower for your property.

And to get a head start on your outdoor spring cleanup, check out CR's ratings of chainsaws, in-ground sprinkler timers, and string trimmers.

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