Basic engine maintenance of your lawn mower is essential to keep your garden in good shape.
1) Always use the fuel and oil recommended by the engine manufacturer.
Check the oil level on the dip stick before each use and top up if necessary.
Keep your fuel fresh. Modern unleaded petrol goes stale if stored for more than 3 months. This will make your mower difficult to start.
To extend the life of stored fuel always store in a sealed fuel can kept in a cool, dry, place and add fuel conditioner (available from your dealer) to fresh fuel. Note: fuel conditioner cannot revive stale fuel but if added to fuel when fresh it can extend its life for up to 2 years.
Avoid using old metal oil cans to store fuel as these can rust on the inside and cause carburettor blockage.
Unconditioned stored fuel over 3 months old may still be used in a petrol engined car where it will cause no problems because of the large volume of fuel in the tank.
2) If you need to access the underside of the mower for inspection or clearing always lift the mower up from the front so that the spark plug points upwards. Never turn the mower on its side even for short periods as this will allow fuel from the carburettor and/or oil from the sump to flow into the air filter or the silencer causing difficult starting and excessive smoking and possible terminal contamination of the air filter element.
3) Keep your spark plug clean and check your air filter regularly.
Sponge air filter elements may be washed in paraffin or even soap and water provided they are dried and re-oiled afterwards. Paper air filter elements cannot be washed and must be replaced if very dirty or contaminated with oil or fuel.
4) Frequently check the tightness of all nuts, bolts and screws on the engine, handles, chassis and blade. Stop using the mower if any bolts or screws are missing until they can be replaced.
5) If the wheels become loose or wobbly, check for wear and replace if required.
6) Keep the drive mechanism on self propelled mowers in good working order. Regularly remove the belt cover to clear accumulated grass and debris and check the condition of the drive belt. Check that the drive cable is adjusted correctly.
7) Have your blade sharpened regularly or replace. Rotary mower blades should be replaced every 2 years to prevent metal fatigue.
8) Clean the underside of the mower preferably after each outing but certainly before the mower is stored for the winter. Grass attached to the underside of the mower will rot creating acids which can damage the mower.
To clean the underside of the mower, first remove the air filter element then tip the mower with plug upwards as described above. You may put the mower on a bench or table with the handles touching the floor so that the mower chassis is vertical. Warning: If there is fuel in the tank this may leak out during this process. Either drain the fuel or take appropriate measures to avoid fire hazard. Clean the underside with a paint scraper and wire brush. Provided the engine is cold you may also use a pressure washer or hose pipe to assist with underside cleaning.
Clean the grass bag or box. A clogged grass collector will block the air flow and cause poor collection.
9) At the end of the mowing season or before storing the mower for extended periods drain the fuel from the tank. If your engine has a carburettor with a float bowl this may also be drained or the engine run with the tank empty to burn off the remaining fuel.
This may also be an opportunity to change the oil which should be done annually or after every 50 hours use whichever comes first.
With the engine warm, the oil can either be drained by removing the oil drain plug under the engine or tipping out from the top. (Remove the air filter element before tipping). Always replace with clean oil immediately. Never leave the oil sump empty.
10) Always store the mower on a level surface. Never lean a mower against a wall or attempt to hang it on a wall or the oil from the sump will migrate to parts of the engine where it is unwelcome.
11) At the start of the new season, check the oil level and refill the fuel tank with freshly bought fuel.
Remember: Much of the above may be beyond the capabilities of the average owner. Your local authorised dealer will be happy to carry out regular servicing and cleaning for you. Don’t wait until something goes wrong. Have your mower serviced annually at the end of the season. If you wait until Spring you will find that your dealer will be very busy and you may have to wait some time before he can service your mower.