Basics of Gas Mower Maintenance
By T. Jeff Williams
There's good news and bad news. The good news is that spring is here. The bad news is that you will have to mow your lawn again. Actually, it doesn't have to be bad at all. Getting your mower in shape for the season makes this task easier and possibly more enjoyable.
Trying to start the mower after it has been sitting idle for the late fall and winter months can be a frustrating experience. If the blade is dull or needs replacement that can add even more frustration.
To help ease your frustration in facing a surly lawn mower again, here's a good, basic rundown on mower maintenance.
The Blade: One of the first things in getting ready for spring mowing is to remove the blade and sharpen it. A dull blade just breaks the grass off rather than slicing it. Torn grass tips quickly turn an unsightly brown, altering the appearance of your lawn.
Before you touch the blade, remove the wire to the spark plug. It's conceivable that turning the blade as you remove it could start the engine. It cannot start with the plug wire disconnected. Because gas will leak out when you tip the mower, remove the cap, put a piece of plastic over the opening and screw the cap back on. Now tip the mower on its side.
Use a wrench, or better, a socket wrench, to loosen the nut holding the blade. If the nut is stuck, dribble some Liquid Wrench on it and let it sit for 20 minutes or so. Put a block of wood under the blade to keep it from moving as you turn the nut counter-clockwise to loosen it.
When the blade is off, sharpen it with a file or a bench grinder. Sharpen both sides equally to that the blade remains balanced. Test this by supporting the blade with a nail through the bolt hole. If one side is heavier than the other, grind off more metal from the heavy side. An unbalanced blade will cause excessive wobble with your mower.
Before you reinstall the blade, take the time to clean the mower underside. Scrape all old grass off and use a screw driver to pry gunk out of narrow spaces.
When sharpened, reinstall the blade in the same position it was. And don't forget to remove the plastic from the gas tank opening.
Spark Plug: With the mower back on all four wheels, remove the spark plug. Look at the tip. If it is tan or light brown in color, it is operating properly. Regardless how the plug looks, it's a good idea to replace it each year. At least have a spare on hand. The plug has an identification number on it, so be sure to get the same type. Different engines use different spark plugs and most generally have different gap settings. Check your manual or look up the engine online to find the correct gap setting.
Use a piece of sand paper to scrape the inside of the wire that connects to the plug so there will be a good electrical connection there.
Air Filter: Filters do valuable work in keeping dust and dirt out of your engine. Remove the filter cap and take out the filter. If it's paper, get a new one. Install with the pleats out. If it's a foam filter and badly worn, get a new one. Pour some engine oil over the foam filter, squeeze it dry (in a rag to keep your hands somewhat clean), and reinstall. A dirty filter will often be the cause of a hard-to-start mower engine.
Carburetor: Don't make any adjustments on the air and gas mix. If the engine was running fine last season, then these settings are likely still good. Just clean around the carburetor and spray all moving parts, particularly the choke and throttle, with some WD40. Spray the linkage on the handle with WD40 too.
Change Oil: No one likes this job but you will see why it's important when you see how dirty the oil is. That dirt is eating up your engine. Put the mower up on saw horses or boards and loosen the oil plug nut on the underside of the engine. Drain the oil into a pan, put the plug back in, and refill. These engines normally use 30 weight oil.
Add Fresh Fuel: Empty out any gas that sat in the tank over the winter. It's always best to drain the fuel during long periods of time. Put in fresh fuel. Water can collect in the gasoline and make your engine difficult to start. Remember, at the end of each mowing season, drain the gasoline and then run the engine until it uses up the last of the gasoline.
Recoil Starter: Spray the mechanism with WD40, using the nozzle to get under the flywheel.
Tighten Wheels and Belts: Check the nuts on the wheels, tighten as necessary, and spray around the axle with WD40. Make sure any belts are snug.
Final Tip: If you have trouble starting the mower and you have gone over all the points above, have a can of Starting Fluid on hand. Just spray some around the air filter, which leads to the carburetor, and crank the engine. It usually works.