The content of the article:
Internal combustion engines used in lawnmowers are two and four-stroke. For users it is necessary to know, the oil for lawnmower with 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, which can not be replaced and mixed.
The role of oil in internal combustion engines
The energy transmitted by the motor shaft to the rotating mechanisms is obtained by adiabatic expansion of the gases at the time of the explosion in the combustion chamber. Due to the movement of the piston in the combustion chamber, gases are compressed. This means that the system works with minimal gaps, and abrasion appears on the mating parts. The gap between the parts increases, and the compression compression decreases, the necessary pressure is not reached to ignite the fuel-air mixture.
So it would be, if the pritereye parts worked without lubrication. Motor oil for lawnmowers, added to gasoline or falling on the nodes of the crankcase, is applied with a thin film between the parts, preventing wear and tear. Since absolutely no wear can be eliminated, the oil flushes the microparticles in the gaps, preventing them from destroying the surface.
The prepared fuel mixture should be used for 2 weeks, remaining in a metal or polypropylene container. Do not store the composition with gasoline in polyethylene bottles. The decomposition products will fall into the mixture, the deposit in the combustion chamber will increase.
The device 2 and 4 stroke types are different and therefore the consistency of the lubricant, the additives in it are different. Each type of conjugate nodes in the mechanisms requires the types of lubrication that correspond to the nature of the movement of this node. What kind of oil is poured into the lawn mower, the manufacturer recommends in the instruction manual.
You can not pour oil, guided, the more expensive, the better. The use of ingredients depends on the class of equipment on the degree of grinding of the conjugate units, operating conditions. The composition of the fuel mixture for two-stroke engines depends on the method of obtaining the basis of antifriction composition. The oil for a lawn mower with 2 stroke engines has a special composition. All oils are separated by the production method:
- mineral;
- synthetic;
- semisynthetic.
This affects their lubricating qualities, the ability to remain liquid when the temperature decreases. But 5-15% in each composition is assigned to additives. This they create an effective composition that prevents:
- corrosion of surfaces;
- thermal stability;
- resistance to decomposition;
- increase alkalinity, preventing oxidation;
- the viscosity is stabilized.
Used with a 4-stroke engine, the lawnmower oil has other additives, viscosity. It also serves to wash the moving surfaces, but does not mix with gasoline. The oil is oxidized, contaminated with scale particles and requires replacement every 50 hours of operation.
The difference in the work of 2 and 4 stroke engines
For two-stroke engines, there are two ways to lubricate the piston system and the crank mechanism:
- adding oil to the fuel in an exact ratio;
- Pour oil separately, the mixture is formed when fuel is injected into the cylinder.
In the photo, the oil is fed through the plunger pump to the inlet port of the combustion chamber.
The second scheme is the future, while in the garden technology the first method is used - the preparation of a combustible mixture. The new engines are low-noise, economical, but they are more complicated.
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 rubbing parts. In this case, the lubrication system consists of a pump, an oil filter and pipes that lead to the components. Can be used crankcase or tank method of lubrication. In the first case, oil is fed into the system from the crankcase and from there it is pumped into the supply pipes by the pump. With a "dry crankcase the droplets of oil collected in the pail are again sent to the tank.
In the photo, a grease with a "wet sump" and a lubricant with a "dry sump".
The difference in the composition of oil for different types of engines is fundamental. The oil for a lawn mower with a 4 stroke engine must remain unchanged for a long time. Composition for two-stroke engines during combustion should have fewer mineral inclusions to prevent the formation of carbon deposits.
If there is a recommended oil, experiment with the selection of another composition should not be. In the absence of - choose the recommended for 2 or 4 stroke models. To use gasoline above the recommended brand - it is premature to replace the burnt out valves, other components.
An important characteristic when choosing a protective ingredient is its operating temperature. The additive should be resistant to heating, but not thicken at low temperatures. Therefore, for each mechanism, depending on the operating conditions, there is an oil brand.
Principal differences of internal combustion systems for the user
Which combustion system is more effective, 2 or 4 stroke? How to understand the user and get the best mechanism? Petrol trimmers and motorcycles with a 4-stroke motor on sale are not found. The push-pull device is much lighter and therefore the trimmer weighs a little and can be controlled by a woman. But there are two-stroke engines and four-wheelers. Other differences:
- different ways of using lubricant;
- environmental friendliness is higher in 4-stroke engine, it is also less noisy;
- easier to repair and maintain 2-stroke engine;
- the service life is longer in 4-stroke, but they have more difficult maintenance due to the replacement of oil in the lawnmower;
- two-stroke engines are easier and cheaper.
The 2-stroke engine used in the lawnmower is inferior to 4-stroke in many technological indicators. With separate supply of gasoline and oil for economy and other indicators, it is preferable for light vehicles. In addition, a separate fuel delivery saves the expense of an expensive component in 4 times.
In the photo, the state of the engine, which worked without oil change for a long time.
The four-stroke engine has a complex lubrication system, and all the more it is necessary to use methods for cleaning the circulating fluid. A filter is installed in the oil system, which prevents clogging of pipes and the pump with scale and other inclusions. As the contamination of this part is replaced.
How to change the oil in a 4 stroke engine
The manufacturer in the instruction manual gives a schedule of maintenance of the mechanisms and the procedure for the production of the work. The lubrication efficiency is reduced after 50 hours of operation. Therefore, an oil change is required. In domestic use for a season does not type such time of use of the device, and to make cleaning of the filter, oil replacement is necessary at conservation. Before changing the oil in the lawn 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 to take the liquid under vacuum.
To do this, make a nozzle and pour out the work into the prepared container. But at the same time a small part, up to 100 ml remains in the crankcase and drains off the filter. This residue should be disposed of, draining the liquid of 5 minutes through the hole. Simultaneously change or flush the filter in the system. After pouring a new lubricant, controlling the level of the probe. Usually, the engine oil is packed in opaque black plastic so that it does not decompose into the light. The required volume is 500-600 ml.
