What is the difference between 4 and 2 stroke lawn mower oil

Internal combustion engines used in lawn mowers come in two and four strokes. For users need to know, 4 stroke lawnmower oil is filled separately from gasoline. For a two-stroke engine, a fuel mixture is prepared with the addition of oil. At the same time, different formulations are recommended that cannot be replaced and mixed.

The role of oil in internal combustion engines

The energy transmitted by the motor shaft to rotating mechanisms is obtained due to the adiabatic expansion of gases at the moment of 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 clearances, abrasion appears on the mating parts. The gap between the parts increases, and the compression compression decreases, the required pressure is not reached to ignite the fuel-air mixture.

This would be the case if the lapped parts worked without lubrication. Motor oil for lawn mowers, added to gasoline or falling on components from the crankcase, is applied with a thin film between the parts, preventing wear and tear. Since it is absolutely impossible to eliminate wear, the oil washes away microparticles in the gaps, preventing them from destroying the surface.

The prepared fuel mixture should be used within 2 weeks, stored in a metal or polypropylene container. Do not store the composition with gasoline in plastic bottles. Decomposition products will get into the mixture, and carbon deposits in the combustion chamber will increase.

The device of 2 and 4 stroke types is different and therefore the consistency of the grease, the additives in it are different. Each type of mating units in mechanisms requires types of lubrication that correspond to the nature of the movement of this unit. What kind of oil to fill the mower is recommended by the manufacturer in the operating instructions.

You can not fill in oil, guided by, the more expensive the better. The use of ingredients depends on the class of technology, the degree of grinding of the mating units, the operating conditions. The composition of the combustible mixture for two-stroke engines depends on the method of obtaining the base of the antifriction composition. The 2-stroke lawnmower oil has a special composition. All oils are separated according to the production method:

• mineral;
• synthetic;
• semi-synthetic.

Their lubricating qualities, the ability to remain liquid when the temperature drops, depend on this. But 5-15% in each composition is assigned to additives. It is they who create an effective composition that prevents:

• corrosion of surfaces;
• heat resistance;
• resistance to decomposition;
• increased alkalinity, which prevents oxidation;
• stabilize the viscosity.

Oil used with 4-stroke engine for lawn mowers has other additives, viscosity. It also serves to wash moving surfaces, but does not mix with gasoline. The oil oxidizes, becomes contaminated with scale particles and requires replacement every 50 hours of operation.

Difference in 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 fuel in an exact ratio;
• pour oil separately, the mixture is formed when fuel is injected into the cylinder.

In the photo, oil is fed through a plunger pump dispenser into the inlet pipe of the combustion chamber.

The second scheme is the future, while the first method is used in gardening equipment - the preparation of a combustible mixture. The new engines are quiet, economical, but more complex.

To prepare a combustible mixture, you can use the table and dispenser.

The four-stroke engine has a container for oil, which is used to protect the rubbing parts. In this case, the lubrication system consists of a pump, an oil filter and pipes that supply the composition to the units. Crankcase or tank lubrication can be used. In the first case, oil is supplied to the system from the crankcase and from there it is pumped into the supply pipes by a pump. With a dry sump, drops of oil collected in the sump are sent back to the tank.

Pictured is a wet sump and dry sump grease.

The difference in oil composition for different types of engines is fundamental. Lawnmower oil with a 4-stroke engine must remain unchanged for a long time. The composition for two-stroke engines should have fewer mineral inclusions during combustion to prevent carbon deposits.

If the recommended oil is available, you should not experiment with a different composition. If absent, select the one recommended for 2 or 4 stroke models. Use gasoline higher than the recommended brand - it is premature to go to replace burnt-out valves and other components.

An important characteristic when choosing a protective ingredient is its operating temperature. The additive should be heat-resistant, but not thicken at low temperatures. Therefore, each mechanism has its own brand of oil, depending on the operating conditions.

Principal differences between internal combustion systems for the user

Which combustion system is more efficient, 2 or 4 stroke? How can the user figure it out and get the best mechanism? Petrol trimmers and a brushcutter with a 4-stroke engine is not on sale. The two-stroke is much lighter and therefore the trimmer weighs a little and can be operated by a woman. But there are two-stroke engines and four-wheeled vehicles. Other differences:

• different way of using the lubricant;
• environmental friendliness is higher in a 4-stroke engine, it is also less noisy;
• easier to repair and maintain 2-stroke engine;
• the motor resource is longer for the 4-stroke, but their maintenance is more difficult due to the oil change in the lawn mower;
• two-stroke motors are lighter and cheaper.

The 2-stroke engine used in the mower is inferior in many technological parameters to the 4-stroke engine. With a separate supply of gasoline and oil in terms of economy and other indicators, it is preferable for light vehicles. In addition, separate fuel supply saves the consumption of an expensive component by 4 times.

The photo shows the state of the engine that has been running for a long time without changing the oil.

A four-stroke engine has a complex lubrication system, and it is all the more necessary to use methods for cleaning the circulating fluid. A filter is installed in the oil system to prevent the tubes and pump from clogging up with scale and other inclusions. This part is replaced as it gets dirty.

How to change the oil in a 4-stroke engine

The manufacturer in the operating instructions gives a schedule for the maintenance of mechanisms and the procedure for performing work. The lubrication efficiency decreases after 50 hours of operation. Therefore, an oil change is required. In domestic use, during the season, such a time of using the device will not be accumulated, and the filter should be cleaned, the oil should be changed 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 for filling the oil in the tank and use a device for taking fluid under vacuum.

To do this, make a nozzle and pump out the mining into a prepared container. But at the same time, a small part, up to 100 ml, will still remain in the crankcase and will drain from the filter. You need to get rid of this residue by draining the liquid for 5 minutes through the hole.At the same time, change or wash the filter in the system. Then fill in new grease, controlling the level with a dipstick. Usually, engine oil is packaged in opaque black plastic so that it does not decompose in the light. The required volume is 500-600 ml.

Changing the oil in the lawn mower - video