Lawn Mower Repair: When to Fix It and When to Bring It In

posted on Friday, December 6, 2019 in How To

There’s nothing more frustrating for a homeowner than lawn care equipment failure. You carved out room in your schedule for a little lawn maintenance only to spend your day searching for a solution to a problem you didn’t know you had.

Meanwhile, your Bermudagrass isn’t getting any shorter.

John Deere riding mowers and lawn tractors are built to last. But there are a number of things that can go wrong due to neglected maintenance, regular wear-and-tear, or the occasional mower malfunction.

With a better understanding of the most common lawn mower problems, a little repair work won’t sidetrack your Saturday.

6 Lawn Tractor and Riding Lawn Mower Repairs You Can Do Yourself

The quickest way to get your lawn mower up and running is to fix it yourself. With the right tools and know-how, you can stick to your lawn care schedule with little delay. Not every mower repair can be done DIY, but these six issues are easy even for the beginner repairman.

1. Oil Change

Changing the oil on your lawn mower is a must. Old, dirty oil can gum up your engine and cause serious damage — putting you in the market for a new lawn tractor earlier than expected. Even running on low oil levels puts your engine, and your machine, at risk.

John Deere recommends checking the oil level on your mower before each use and changing the oil once per season. Early spring, before the Southeast mowing season gets going, is always a good time. Check your operator’s manual for a maintenance plan specific to your machine.

If you’re in the middle of mowing and the engine starts knocking, chances are the oil is low. Stop what you’re doing and fill up on oil. Low oil levels can also keep your engine from starting. If you can’t even get your lawn mower out of the garage, fill it little by little until the engine is able to fire.

2. Spark Plug Replacement

Oil isn’t the only thing that can cause engine issues. Faulty or dirty spark plugs can also derail your mowing plans. A rough ride on your lawn tractor or difficulty getting it started are both warning signs. If you check or change the oil and are still experiencing the same problems, inspect the spark plugs.

Your lawn mower can’t start without working spark plugs. You should regularly inspect the connection and clean off any dirt or grime that may be causing connectivity issues. And once per season or every 100 hours, whichever comes first, John Deere recommends replacing spark plugs.

It takes just 15 minutes. With the mower shut off and on a flat surface, loosen the spark plug wires and remove the spark plug. A good-working spark plug will look clean. If it’s dirty or has damage, toss it out. Before installing a replacement spark plug, set the gap according to the specifications of your machine before you put it in and tighten it.

3. Battery Replacement

The battery powers as much of your riding mower as the engine. Similar to spark plugs, corrosion and loose connections can cause electrical issues. Your machine won’t even start if the battery is dead.

Open up the hood of your riding lawn mower or lawn tractor. If the battery is corroded or testing shows it can’t hold a charge, you need to replace it. Loosen and remove the bolts on the terminals, being careful not to touch both at once. Remove the old riding mower battery and slide the replacement in. Reconnect the red wire to the positive side and the black wire to the negative side and re-install the bolts to hold it in place.

4. Blade Sharpening

You wouldn’t think flimsy blades of grass are any match for sturdy, steel mower blades. But all blades dull over time — especially lawn mower blades that handle tougher terrain or frequently mulch up yard debris.

Ragged or unevenly cut grass could be a sign of a dull, loose, or unbalanced blade. Lift up your mower with a jack to check it out. You may simply need to tighten things up to reduce blade vibration. But you should sharpen your mower blades at least once a year to keep them in cutting shape.

And if you can sharpen a blade, you can just as easily install a replacement. Lawn mower blades that are bent, uneven, or damaged should be replaced.

5. Belt Replacement

Belts control the mower blades. If replacing the blades doesn’t fix your issue, or your mower isn’t cutting grass at all, the blade drive belt is at fault. It spins the lawn mower blades in the cutting motion. If it’s worn or broken, replace it while you’re under the deck.

A different drive belt controls the movement of your machine. A riding lawn mower or lawn tractor that doesn’t budge when you put it in gear or slows going uphill may have an issue with the riding mower drive belt. It could have simply slipped out of place, worn down, or broken altogether. Slide it back in place or install a new one to get your mower moving again.

Both drive belts are located under the mower deck, so consult your operator’s manual to be sure you’re dealing with the right one.

6. Tire Repair and Replacement

Riding lawn mower and lawn tractor tires are durable and rugged. But they are filled with air, so they can fail from breaks, cracks, and punctures. Like all types of tires, they do wear out over time.

It’s easy to tell when a tire’s gone flat. Catching a leaky or old tire before it fails is a little harder. You may not notice anything with a visual inspection of the tire, but you might notice a difference in your lawn. A bad tire can lead to uneven cuts.

If a pressure check turns up a leak, seal it. If the tire is too worn or damaged, it’s time for a replacement. And it’s a little bit different than swapping out a tire on a truck. With mowers, you have to remove the tire from the rim and install the new one in its place. Also, the front tires and back tires are different. Check your riding lawn mower or lawn tractor owner’s manual for specifics on which tires you need and the correct steps for replacing them.

When to Call for Lawn Mower Repair Service

Oil, spark plugs, battery, tires, blades, and belts are all relatively quick and painless tasks you can handle at home. You probably have all the tools you need right there in your garage or shed. With a quick trip to your local TriGreen dealer or our parts website, you can get the John Deere replacement parts you need to get up and running again.

As John Deere’s line of lawn tractors, riding lawn mowers, and Zero-Turn Mowers gets more advanced, even common repairs can push you out of your comfort zone. That’s how you know it’s time to bring your machine into your nearest TriGreen lawn mower repair shop.

Small engine repairs, in particular, can be tricky. You might be able to find a how-to or video online showing you generally how to fix some type of lawn mower carburetor, engine, or other part. But it’s unlikely that it’s your specific machine, which makes it difficult to follow along and complete repairs correctly. Any engine issues you can’t clear up with the oil, spark plugs, or even the belts should be looked at by a John Deere factory-certified technician.

TriGreen Equipment service experts are specifically trained in the brand’s equipment and know the ins and outs of each mower. And all the tools and parts are on-hand. On more serious repairs, you can often get your lawn mower back from the repair shop faster than ordering a replacement part and doing the work yourself.

Staying on top of your mower maintenance is important to the health of your machine and your lawn. The service team can also perform tune-ups and routine maintenance to preserve the health and extend the life of your riding mower or lawn tractor.

But either way, if the repair is something you can DIY or have your local dealership do, you can pinpoint the problems early so your mower spends more time on the grass than laid up in the garage.