Lawn mower care: Our tips and tricks for maintenance

Sharp blades and smooth-running levers

The rotating blade is the heart of the mower. If it is blunt or even damaged by stones, the cuts on the blade of grass become very unclean. A blunt blade tends to tear off the grass and does not cut it smoothly. This damages the blades of grass, the lawn has to put more energy into the regeneration of the cuttings and therefore prevents a lush green lawn from forming. The lawn mower blade should therefore be checked for sharpness, cracks or nicks at the beginning of each season and resharpened if necessary. It is generally advisable to check the mower blade regularly, even during the gardening season and after collisions with stones. In the case of severe damage to the cutting surface, repair is usually not worthwhile; in this case, the only solution is to replace the blade.

Experienced tradespeople can sharpen the blade themselves in spring. However, we recommend having this done by a specialist dealer or buying a new lawnmower blade. Improper sharpening can result in imbalances – similarly to with car tyres. Due to these imbalances, the blade will later rotate unevenly during mowing because it still breaks out at the top and bottom. This puts unnecessary strain on the motor bearing and increases its wear. The quality of the cut also suffers. In the Einhell Service Shop you can easily select and order the right blade for your tool.

Next, check that all levers can be moved and that the grease inside the Bowden cables has not hardened over the winter. If the levers can only be moved with difficulty, a drop of oil on the joints and in the Bowden cable usually helps. After moving the lever gently a few times, the oil should have spread along the cable, and everything should be working again.

Cleaning the catcher and mowing deck

If the catcher for the cut grass is not completely made of textile fabric, it will have ventilation slits on the side and on the back. You can easily clean the slots with an old dish brush. However, not only the plastic catcher bag, but also textile catcher bags should be cleaned to prevent mould growth, among other things. Because only if the air sucked in by the mower can escape freely will the grass cuttings land cleanly in the catcher box, so that it is optimally filled and as few cuttings as possible remain on the lawn.

Now it's time for the space under the lawn mower, known as the mowing deck. Grass cuttings, especially when they are damp, tend to stick under the lawn mower and harden there. These stuck-on cuttings need to be removed as part of the maintenance, so that the metal parts of the mower do not start to rust due to the moisture of the wet lawn. The same applies to the wheel suspension! In general, the cleaner the mower deck, the better the air circulation in the chassis and thus also the cutting result and catching behaviour.

Checking the starter rope

First take a look at the starter rope for the motor. It can become brittle over time or even break off completely. If the rope is no longer in good condition, you should replace it immediately. A repair is usually no longer possible.

Checking the spark plug and ignition spark

Now comes the spark plug. To check its condition, unscrew the spark plug from the motor and visually inspect it. If the electrodes still have a metallic or fawn colour and are not covered in soot, the spark plugs can generally still be used for another season. Slight discolourations of the electrodes can be removed with a simple wire brush. However, if the spark plug is black or even completely oily, there is a defect in the system which must be repaired urgently. When buying new spark plugs, always ensure that the type designation is correct. You'll find this on the ceramic body.

Checking the carburettor and primer

If you have not already cleaned the dirty carburettor during the winter, you should now check again whether cleaning is necessary. In the immediate vicinity of many models is the so-called primer: a manually operated fuel pump which fills the carburettor with fresh fuel in a few pump strokes. This is particularly useful if it has been run empty or has run empty over the winter. Also check its functionality with a few pump strokes.

Checking the air filter

When mowing, dust and small grass cuttings whirl around the mower, so it's no wonder that the motor sucks in small particles which gradually clog the air filter. If the air filter is clogged, the more gets no more air, dies out and will not start. Depending on the type of filter, it may be sufficient to tap the filter regularly and apply a little air filter oil. If it is too dirty, you must replace it. A petrol motor can only start and run properly with a clean air filter.

Checking the oil level

Since a petrol lawn mower needs to be well lubricated just like a car, the oil level has to be checked regularly. On most lawn mowers, the oil dipstick is found in the cap of the oil filler tube itself. Pull out the dipstick, wipe it with a clean cloth and reinsert it. Then pull it out again and check that the oil residue is within the min. and max. marks. If there is not enough oil, refill it to the required amount. However, the oil level should be checked not just at the start of the season, but at regular intervals, so that all moving parts in the engine of the lawn mower are well lubricated and thus do not overheat.

Depending on the age of the engine oil, it may be time for an oil change. You should use the following intervals as a general guide:

• For a commercial 4-stroke lawn mower with normal use: once a year, ideally in the spring.
• For a petrol mower with heavy use: every 25 operating hours.
• For a newly run-in lawn mower: first oil change after 5 to 6 hours of operation. 

These short change intervals compared to a car are mainly due to the fact that the petrol motor in lawn mowers usually do not have an oil filter, which makes the oil dirtier more quickly. However, for safety reasons, please refer to the instruction manual. There you will also find information about what oil the engine needs and the intervals at which it must be changed. For more information on engine oil, petrol and the maintenance of petrol-powered equipment, read this article.

Emptying the tank

Old fuel loses its ignitability in winter and can clump together. Therefore, you should completely empty the petrol lawn mower's fuel tank before winter. Then you only need to fill it up again in spring. If you left petrol in the tank over the winter, it is safer to empty it now and fill it with fresh fuel.