Lawnmower maintenance and maladies
By Tom Phelan - ReminderNews
Featured Article - posted Wed., Apr. 25, 2012
You may have already heard your neighbor fire up the lawnmower for the first time this spring. If that doesn’t make you feel a little guilty, it should at least remind you to prepare your own machine for the first cutting. Before you pull the cord or turn the key, be sure to address the basics to keep your mower running properly.
There are two very important things to remember whenever you work on a lawnmower: wait until the engine is cool, and always disconnect the spark plug cable and tuck it out of the way. Make a habit of these two fundamentals, and you will avoid dangerous mishaps.
The simplest area to check and maintain is the air filter. It usually has a single retaining screw through its cover, which conceals a paper or foam filter element. This filter keeps dirt, dust and grass and other matter from being drawn into the chamber where air mixes with fuel. It needs to be kept in good condition.
Clean out a pleated paper filter with a soft bristle brush and/or by tapping it against a solid surface. If it doesn’t easily come clean, replace it. Wash foam filters with a little dish detergent and water, then thoroughly rinse and dry them. These filters also need to be saturated with a little engine oil before being replaced. Make a habit of removing and cleaning the filter after each mowing session. That way you will know whether it needs to be replaced before the next use. Filters should be replaced after 25 hours of use - at least once each season.
Small engines are air-cooled, and most manufacturers specify 30W oil in the crankcase. Check the oil while it is warm. Make sure the level on the dipstick is within the marks for acceptable oil quantity. The oil is light amber in color when it comes out of the bottle. Over time - usually about eight hours of use - it will turn dark, indicating it should be replaced. Get an empty disposable container, find the drain plug and remove it while capturing the oil in the container. It may be just as easy to tilt the mower and drain the oil through the filler tube. Dispose of the oil in a responsible manner, and carefully refill the engine crankcase with the proper amount of clean 30W oil.
If you didn’t remove the cutting blade(s) when you put the mower away last fall and take them into the shop for inspection and sharpening, take care of that now. Remove the blade by tipping the mower up and properly stabilizing it in that position. Jam a block of wood between the blade and the housing. The blade is probably fastened to the drive shaft with a single hex-head bolt.
Inspect the blade for damage, including excessive wear at the cutting surface, as well as nicks and burrs. If it appears bent, or you felt a vibration the last time you used it, it needs replacement. Depending on how much use your machine gets, the blade may last a few years before it needs to be replaced. A balanced blade is essential for smooth running of your machine, and a well-sharpened blade is likewise important for effective cutting of the grass.
Each time you finish mowing, rinse out the underside of the blade housing with a garden hose. Clean off all the cables, wheels, belts and other accessible moving parts. Lubricate the cables with light oil applied directly to the cable, and exercise the cable several times through its sheath.
When you used the machine for the last time last year, you should have either emptied all the fuel or treated it with fuel stabilizer. It is good practice to start each season with fresh fuel and fresh oil in the crankcase. If you are having a difficult time getting the machine started this year, that should be your first area of concern.
Spark plugs can last a long time, but if yours has been installed since ‘you don’t know when,’ buy a new one. Consult the owner's guide for the correct replacement. The gap is already set; all you have to do it lubricate the threads with light oil and hand-tighten it in the cylinder. A quarter turn of the socket wrench should be all it needs to seat it snugly.
When all your maintenance is compete, start it up. If at first it doesn’t fire up, check to be sure that you reconnected the spark plug cable. Then be sure you refilled the gas tank. Prime the line as prescribed in your owner's manual, and try again. Machines that are hard to fire up or that start and die quickly are usually victims of bad fuel.