In contact with metal surfaces in friction, the engine oil is gradually loaded with wear residues. (Non-contractual photo, does not necessarily reflect the drawing)
In addition, the high temperature to which it is subjected slowly degrades its physical characteristics (viscosity) and chemical (corrosion protection); so you have to change it periodically.
The emptying interval is indicated in the machine's maintenance manual, which also specifies the capacity of the crankcase and the type of oil to be used.
The operation is carried out on average twice a year and, at least, every 50 hours of operation. This is an important operation, where a complete inspection of the machine is required: blade (fixing and sharpening), spark plug, filters, control cables; take the opportunity to inject some oil into the control cable ducts at the burette.
Path to follow
Draining must always be done when the engine is hot: the oil, very fluid, then flows perfectly and causes all accumulated impurities. Disconnect thread of the candle and check that there is not a lot of fuel left in the tank if the operation requires you to put the machine down to access the drain plug.
It is always at the lowest part of the crankcase. In principle, however, it is necessary to put the machine back flat so that all the oil flows properly. Before unscrewing the drain plug, remove the filler plug to facilitate the flow of oil. Place a container under the drain hole large enough to hold all the oil drained.
Warningthese oils should not come into contact with the skin (cancer risk), of course not with the eyes. To empty, you will need to wear safety goggles and gloves.
Legislation prohibits the discharge of used oil into the sewer or into the nature, as well as their burning which generates toxic discharges into the atmosphere (dioxin, greenhouse gas). Collect dump residues in a can, which you will carry in a dump or at a garage (indeed, some participate in the operation of recovery of the draining oils). To find the collection points, contact your town hall. Do not mix all your used oils, specific containers are at your disposal in the waste disposal centers. The discharge of waste oil into the wild is punishable by fine which can reach up to 1000 euros.
When the oil does not drip, clean the drain and fill holes using a clean, lint-free cloth. Tighten the drain plug without forcing (otherwise you may damage the thread). If it has a metal seal, change it.
Pour the amount of oil indicated in the service manual through the filler hole. Allow the oil to disperse for 10 to 15 minutes and check that the correct level is reached; if necessary, complete the level.
It is rare that the oil can be poured directly; it is necessary to use a funnel. The top of a plastic mineral water bottle can be used. Be careful not to allow dirt to enter the housing.
As a precaution, it is recommended to place a gauze screen in the neck of the funnel. Replace the filler cap and, if necessary, wipe the burrs with oil.
Which oil to use?
Only four-stroke engines, and a few rare two-stroke engines with separate lubrication, drain. A classic two-stroke fueled by the mixture does not drain. For the lubrication of a mower, a standard engine oil is perfect. In almost all temperate climates, a 10 W 40 oil is ideal for four-stroke gasoline mowers. A 10 W 30 oil loses its characteristics for use at an ambient temperature above 35° C.
For use in a very hot climate, a 20 W 50 oil, or even a SAE 40 or 50 monograde oil is recommended. Conversely, for work in a cold climate use at least one SAE 10 or 20 oil.
The letters API usually found on one of the smaller sides of the can indicate that the oil has been tested by the American Petroleum Institute, which is a guarantee of product quality.
The letter S concerns gasoline engines and the letter C is reserved for diesel engines. These two letters are followed by another (sometimes another and a number) to establish a classification according to manufacturers' requirements.
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