Routine maintenance keeps lawn mowers running sharp

Monday, July 31st 2000, 12:00 am
By: News On 6

Don't try to tell Jim Hartley any tall grass stories - he's heard them all.

Those stories usually come in the spring when a distraught lawn owner tows his badly neglected mower into Mower Medic, Mr. Hartley's Carrollton shop. Then the real bad news hits: that grass is going to get longer in the weeks that lawn mower has to stay at the shop. And you can bet the mower owner is going to be out some green.

"This is definitely one of those deals where you pay me now or pay me later," Mr. Hartley says. "You can buy a few parts and do the work yourself or pay bigger money later to have someone fix" a wrecked engine.

Let's face it: We take our cars to the lube shop every couple of months but might rarely think to change the oil in the lawn mower. We shower after cutting the grass, but does the mower get a cleaning?

If at this point in the mowing season, you haven't done any maintenance since your spring tuneup, it's time to give your mower a little TLC. And if the idea of a spring tuneup seems foreign, take a moment to schedule end-of-season maintenance.

"If you don't give love to the lawnmower, the lawnmower won't give love back to you," says Garrett Gray of Duncanville. Mr. Gray, 36, knows a thing or two about lawnmower maintenance - he races a riding mower for the U.S. Lawn Mower Racing Association and is president of the state chapter.

There are three keys to keeping your lawnmower happy - and hence keeping your lawn well groomed: regular maintenance, an annual tuneup and off-season care.


Most mechanics agree half the battle is keeping the mower clean - inside and out.

"I see that on a weekly basis," says Dean Emmitt of Audelia Lawn Equipment Service of Dallas. "People go seven, eight years without maintaining their mower, then they bring it in. They say, 'Well it ran great for seven years and now it won't start.' And I ask them if they've ever changed the air filter, and they say, 'The what?' "

Change the oil and clean the air filter at least twice a season, mechanics recommend.

"Preventive maintenance, especially the air filter, makes the mowers so much more efficient," Mr. Hartley says. "But when they do need service or are to the point where the mower is shut down, the problem is usually that it has ingested too much dirt."

Since most lawn maintenance equipment runs with air-cooled engines, they are constantly sucking in dirty, dusty air. Once the air filter is dirty, all that dirt goes directly into the oil and acts as a grinding agent, wearing away engine parts from the inside.

"Dirty oil just wears everything out," Mr. Emmitt says.

To prevent that, just remove the air filter after every couple of uses and tap it on the ground to clean it, mechanics say. Get a new filter at least once a year.

Owners should plan on some maintenance almost every time the mower is used, from simply cleaning the grass off the deck to regularly sharpening the blades.

Grass, especially wet grass, flies off the blade and sticks under the mowing deck. If not removed regularly, that old grass will literally choke the mower.

"I've seen people come in here with 20 pounds of buildup under there," says Ken Lowery of Mower World in Duncanville. "There's no room for air flow under those decks, and they won't do a good job cutting, bagging or mulching."

Mr. Lowery suggests running a quick hose under the deck to wash it out, or brushing the grass away with a small broom. Be careful not to soak the engine with water.

Mr. Lowery, who has been working on small engines for 44 years, says a neglected mower will live only about six or seven years. But he has seen well-maintained mowers survive 15 seasons or more.


An annual tuneup, in addition to regular maintenance, is easy and cheap and can be done relatively quickly. For those who don't mind dirty hands, the payoff is a more efficient machine and savings from shop repair bills.

"A customer should be able to change the oil, filter and plugs pretty easily on any mower," says Bill Tuggle, service manager for Richardson Saw and Lawnmower.

Mr. Gray says that's true even of people who are completely inept with tools. "If you can open a child cap lock, you can do this type of thing,"

An annual tuneup - which should be done before or after the heavy mowing season from April through September - costs about $55-$75 for most walk-behind mowers. But more than the money, repair shops everywhere get backed up for weeks in the springtime because everyone waits for the tall grass before needing a mower.

"Don't wait until its spring to do the general service," Mr. Emmitt says. "People always wait until it's time to cut the grass, then they wonder why it takes three weeks (in the shop). It's because EVERYONE waits, too."


The next most important step to an efficient machine, the mechanics say, is fresh gas. All of the additives in today's gasoline, which can reduce harmful emissions, also cause it to break down. In other words, gas only has a shelf life of about 30 days. After that, it wreaks havoc with small engines.

"The shelf life for gas is not good," Mr. Emmitt says. After the grass-growing season is over, people tend to leave the gas in their outdoor machines all winter. When that machine is started months later, the bad gas hurts the engine.

To prevent such mishaps, the mechanics suggest treating gas with a fuel stabilizer. That will keep stored fuel fresh, but it's also important to run the machines dry after the season, they say.

Mower owners who practice regular maintenance, give it an annual tune-up and off-season care will enjoy the reliable, efficient performance. That translates into a well-groomed yard - and no springtime tall grass emergencies to unload on your local small engine mechanic.

Dennis Huspeni is a Richardson free-lance writer.

Here are tuneup and maintenance tips for your lawn mower, culled from Dallas-area small-engine mechanics. An important safety reminder: always disconnect the spark plug before performing any maintenance.

Blade sharpening

If the mower misses blades or grass, or the tops of the grass blades have a ragged cut, the mower blade needs sharpening.

Tip mower only on the side OPPOSITE the spark plug. Tipping it any other way will cause oil to run where it shouldn't.

The blade must be removed in order to sharpen properly.

Most blades can be removed with a 9/16-inch, or a 14-millimeter, socket. Use a six-point socket to prevent stripping.

Use a wood block, then your foot, to hold the blade in place while loosening bolt. Use a glove to cover the hand that will hold the blade.

Clamp the loose blade on a table top, and then use a metal file to sharpen. If there are chinks in the blade, it must be sharpened with a stone. "Drill-bit" stones that fit on hand drills don't usually work.

Most mechanics suggest having two blades on hand, so that a sharp one can be used while the other blade is being worked on.

Usually for $6 to $7, a shop will sharpen the blade with a stone, at a proper 30-degree angle. If they have to remove the blade, it will cost $12-$13.

Be careful to fully tighten blade when attaching to the mower.

Even if you perform the annual tuneup yourself, it's a good idea to have a trained mechanic look the machine over at least every two or three years. Their trained eyes can spot worn belts, bad cables or other subtle problems owners might miss.


For more information on small-engine maintenance, check out the following resources:

Small-engine manufacturer Briggs and Stratton runs a Web site with engine maintenance tips at

Helpful books include: Walk-Behind Mower Service Manual (Intertec, $27) and String Trimmer and Blower Service Manual (Intertec, $27). Both books include most all small-engine manufacturers.

Sears HomeCentral Parts and Repair Center, 2270 Valley View Lane in Farmers Branch offers more than 4 million parts for small-engine machines. The 5,000 square-foot store sells parts from more than 400 manufacturers. To order the parts by phone, call 972-620-5038. To look up parts and accessories on the Web, go to

Oil changing

Check the machine owner's manual for specific guidance.

Change the oil in your mower regularly, every 25 hours of mowing (which translates to about two or three times a season).

Oil is bad if it is thin, black and smells dirty or burned.

The conventional way to drain the oil is to loosen the oil plug on the bottom of the deck. But many mechanics say it's just as easy to pour it out of the dipstick opening. Be sure to twist a plastic baggie under the gas cap before tipping the mower to the dipstick side. Lift the rear wheel opposite the dipstick side to completely drain. This method can be done without tools, and without messing around near the blade.

Use only SAE 30-weight, heavy-duty oil. Do not overfill.

Check the oil level before every use.

Air filter and spark plug

Buy a new air filter at least once a year.

Pull the air filter after every couple of mowings. If it's the "paper" style filter, it can be tapped on the concrete for temporary cleaning. The "foam" style filters need to be washed in soapy water, dried in a towel, then soaked in 30-weight oil.

Change the spark plug at least once a year. Most plugs come pre-gapped out of the box so be careful not to drop the plug or bend the metal top.