Internal combustion engines used in lawn mowers are two and four stroke. For users you need to know the oil for a lawn mower with a 4-stroke engine is poured separately from gasoline. For a two-stroke engine, a fuel mixture is prepared with the addition of oil. At the same time, different compositions are recommended that cannot be replaced and mixed.
The role of oil in internal combustion engines
The energy transmitted by the engine shaft to the rotating mechanisms is obtained due to the adiabatic expansion of gases at the time of the explosion in the combustion chamber. Due to the movement of the piston in the combustion chamber, gas compression occurs. This means that the system works with minimal gaps, abrasion appears on the mating parts. The gap between the parts increases, and the compression compression decreases, the required pressure is not reached for ignition of the fuel-air mixture.
So it would be if the ground parts worked without lubrication. Motor oil for lawn mowers, added to gasoline or falling onto the crankcase assemblies, is applied with a thin film between the parts, preventing wear and tear. Since it is absolutely impossible to eliminate wear, oil washes out microparticles in the gaps, preventing them from destroying the surface.
The prepared fuel mixture should be used for 2 weeks, stored in a metal or polypropylene container. You can not store the composition with gasoline in plastic bottles. Decomposition products will fall into the mixture, soot in the combustion chamber will increase.
The device 2 and 4 of the cycle types is different and therefore the consistency of the lubricant and additives in it are different. Each type of mating units in the mechanisms requires types of lubricant that correspond to the nature of the movement of this unit. What kind of oil to fill in the mower, the manufacturer recommends in the instructions for use.
You can not fill in oil, guided by the more expensive, the better. The use of ingredients depends on the class of technology on the degree of grinding of the mating units, operating conditions. The composition of the combustible mixture for two-stroke engines depends on the method of obtaining the basis of the antifriction composition. Oil for a lawn mower with a 2-stroke engine has a special composition. All oils are separated by the method of preparation:
Their lubricating qualities and the ability to remain liquid at lower temperatures depend on this. But 5-15% in each composition is reserved for additives. This they create an effective composition that prevents:
- surface corrosion;
- thermal stability;
- resistance to decomposition;
- increase alkalinity, preventing oxidation;
- stabilize viscosity.
The lawnmower oil used with a 4-stroke engine has other additives, viscosity. It also serves to wash moving surfaces, but does not mix with gasoline. The oil is oxidized, contaminated with scale particles and needs to be replaced every 50 hours of operation.
The difference in the operation of 2 and 4 stroke engines
For two-stroke engines, there are two ways to lubricate the piston system and crank mechanism:
- adding oil to the fuel in the exact ratio;
- pour oil separately, the mixture is formed when the fuel is inlet into the cylinder.
In the photo, the oil supply through the plunger pump dispenser into the inlet pipe of the combustion chamber.
Video: What Oil To Pour Into A Makita 500 Lawn Mower
The second scheme has a future, while the first method is used in gardening. the preparation of a combustible mixture. New engines are quiet, economical, but more complex.
To prepare a combustible mixture, you can use the table and the dispenser.
The four-stroke engine has an oil tank, which is used to create protection for the rubbing parts. In this case, the lubrication system consists of a pump, an oil filter and tubes leading the composition to the nodes. A crankcase or reservoir lubrication method may be used. In the first case, oil is supplied to the system from the crankcase and from there pumped into the supply tubes. With a "dry sump" drops of oil collected in a sump are again sent to the tank.
In the photo, wet sump grease and dry sump grease.
The difference in oil composition for different types of engines is fundamental. Oil for a lawn mower with a 4-stroke engine should maintain a constant composition for a long time. The composition for two-stroke engines during combustion should have less mineral inclusions in order to prevent the formation of soot.
If you have the recommended oil, you should not experiment with the selection of another composition. If not, select the recommended for 2 or 4 cycle models. Use gasoline above the recommended brand. prematurely go on to replace burned-out valves, other components.
An important characteristic when choosing a protective ingredient is its operating temperature. The additive must be resistant to heat, but not thicken at low temperatures. Therefore, for each mechanism, depending on the operating conditions, there is a brand of oil.
Fundamental differences between internal combustion systems for the user
Which combustion system is more efficient, 2 or 4 stroke? How to understand the user and purchase the best mechanism? There are no gas trimmers and lawn mowers with a 4-stroke engine for sale. The two-stroke is much easier and therefore the trimmer weighs a little and a woman can control it. But there are two-stroke engines on four-wheeled vehicles. Other differences:
- different ways to use grease;
- environmental friendliness is higher with a 4-stroke engine, it is also less noisy;
- easier to repair and maintain 2 stroke engine;
- 4-stroke engine life is longer, but they have more difficult maintenance due to oil change in the lawn mower;
- two-stroke motors are lighter and cheaper.
The 2-stroke engine used in the lawnmower is inferior to the 4-stroke engine in many technological indicators. With a separate supply of gasoline and oil for efficiency and other indicators, it is preferable for light vehicles. In addition, a separate fuel supply saves the expense of an expensive component by 4 times.
In the photo, the condition of the engine that worked without changing the oil for a long time.
The four-stroke engine has a complex lubrication system, and all the more it is necessary to use circulating fluid cleaning methods. A filter is installed in the oil system that prevents clogging of the pipes and pump with scale and other inclusions. As it becomes dirty, this part is replaced.
How to change the oil in a 4-stroke engine
The manufacturer in the operating instructions gives a schedule for the maintenance of the mechanisms and the order of production. Lubrication efficiency decreases after 50 hours of operation. Therefore, an oil change is required. In domestic use for a season, this time of using the apparatus will not be typed, and the filter must be cleaned, oil must be replaced during conservation. Before changing the oil in the mower, it is necessary to increase the fluidity of the fluid, start the engine and allow the system to warm up.
It is necessary to unscrew the plug to fill the oil in the tank and use the device for taking fluid under vacuum.
To do this, make a nozzle and pump out mining into a prepared container. But at the same time a small part, up to 100 ml still remains in the crankcase and drains from the filter. This residue must be disposed of by draining the liquid for about 5 minutes through the hole. Change or flush the filter in the system at the same time. After filling in new grease, checking the level with a dipstick. Typically, motor oil is packaged in opaque black plastic so that it does not decompose in the light. The required volume is 500-600 ml.