Which Gasoline Is Poured Into A Lawn Mower

What you need to know about the running-in and operation of four-stroke air-cooled gasoline engines installed on garden, construction and road motorcycle equipment

Gasoline four-stroke air-cooled engines are widely used in landscape gardening equipment. tilleries, motor cultivators, lawn mowers, snow blowers, motor pumps, mini tractors, on construction and road-building equipment. gas generators, vibrating plates, rammers.

Before starting engine operation LEARN INSTRUCTIONS FOR USE. Many buyers, unfortunately, do not. Therefore, the most basic questions on the use of the motor arise.


First: what kind of gasoline should be used.

We recommend the use of clean, fresh, unleaded gasoline with an octane rating of AI92. Air-cooled engines are not designed for use with AI95 and AI98 fuels. The 95th and 98th gasoline contains additives that have a detrimental effect on the piston system of the engine, leading to overheating and breakdown.

Do not mix oil with gasoline. This may result in engine malfunctions that are not covered by the warranty.


Secondly: what kind of oil is poured into the crankcase.

Many consider automobile oil of well-known brands to be the best for use in tiller engines (motor cultivator, snowmobile, electric generator, motor pump, etc.). This is completely wrong. Car oils are designed to work in water-cooled engines, not air. The boiling point of automobile oils is lower than that of oils that contain special additives for air-cooled engines.

Use oil with a quality class of SF, SG, SH, SJ, CD or higher. Do not apply oil additives. Select oil viscosity based on ambient temperature.

SAE 30 (5 ° C and above) is recommended for temperatures above 5 ° C. When used below 5 ° C, it can cause a difficult start.

10W-30 (-18 to 38 ° C) is recommended for variable temperatures. This oil provides a cold start to the engine, but can lead to increased oil consumption at temperatures above 27 ° C.

Check the oil level more often at elevated air temperatures.

Synthetic 5W-30 (-30 to 40 ° C). Synthetic oil provides engine operation over the entire temperature range, as well as easy starting and low oil consumption.

5W-30 (5 ° C and below) is recommended for use in winter conditions.


Always check the oil level. The level should be at the last thread of the filler neck in the horizontal position of the engine (as shown in the figure). Fill and drain holes are located on the front and rear of the engine.

Engine Oil Fill Level

On lawn mowers, pay attention to the dipstick. On the engine probe with a vertical shaft, marks are indicated.

Different engines have different crankcase volumes. If you have a 4, 5.5, 6.5 or 7 hp engine then you need to pour 600 ml. oils. In engines of 7.5 hp poured 900 ml. In engines with a capacity of 8, 9, 11, 13 and 15 hp respectively 1.1 liters.

Third: starting the engine.

At the first or cold start of the engine, an increased load on the piston system occurs. High speeds can damage the motor. Therefore, it is necessary to start the engine at 1/3 of the gas position. And you need to run in at medium speeds.

Fourth: how the engine breaks in.

Air cooled engines "do not like" idle move. Start the engine, warm up for 1-2 minutes. and run in work. During break-in, try to adhere to 50-75% of the load and take mandatory breaks in work after 20-25 minutes. After a break, when the engine has cooled down (15-20 minutes), you can continue to work again. In this mode, the engine should run for the first 4-5 hours, after which the oil must be replaced. Break-in is over.

The main causes of engine failures

REMEMBER. Engine failures occur mainly from improper use.

The first reason for the breakdown is an unopened fuel cock.

When the engine is not running and the fuel valve is open, the carburetor will be transfused and "flooding" candles. Also gasoline enters the crankcase. And this will lead to excessive pressure during engine operation and squeezing out the seals. Then this mixture of gasoline and oil will enter the combustion chamber and through the exhaust valve into the muffler. Gradually, the muffler will become clogged with oil residues and the engine will lose traction.


The second reason for failure: during transportation or storage, the engine was turned over.

Since the engine is 4-stroke. gasoline is poured into the tank, oil in the crankcase. and they should not mix. After a coup, these components are usually mixed in a carburetor. After that, the engine will need to be disassembled and cleaned.


And the third reason for the breakdown: improper starting of the motor with a manual starter.

Many users of four-stroke engines think that the more you pull the starter handle, the better the engine will start. This is not true. The starter handle must be pulled until the cams engage and then gently, but with a large amplitude, pull up. And the engine (if it is working of course) will certainly start.

Video: Which Gasoline Is Poured Into A Lawn Mower


Engine Maintenance Table

Which Gasoline Is Poured Into A Lawn Mower

Good luck to you.

Call 7 (963) 723-00-43. We will be happy to answer questions related to the operation of air-cooled engines Honda, Briggs&Stratton, Mitsubishi, Subaru-Robin, Lifan, Carver, Loncin, Champion.

  1. Why do I need lubrication?
  2. Features of a four-stroke engine
  3. Selection recommendations
  4. How often do you need to change grease?
  5. Change of oil
  6. What kind of oil should not be added?

Lawn mowers have long taken their place among the necessary equipment from the owners of suburban and private houses, as well as employees of park facilities. In the summer, such equipment is operated quite intensively. For reliable and durable operation of lawnmower engines, the quality of fuels and lubricants, in particular oils, is important. About oils for 4-stroke engines of this type of garden machines and is described in this article.

Why do I need lubrication?

Gasoline engines of lawn mowers are internal combustion engines (ICE), in which the driving force transmitted from the ICE to the working bodies (cutting knives) is generated due to the energy arising in the combustion chamber of the cylinder when the fuel mixture is ignited. As a result of the ignition, the expansion of gases occurs, forcing the piston to move, associated with the mechanism for further transfer of energy to the final organ, that is, in this case, the knives of the mower.

Thus, in the engine there are many large and small parts that need lubrication in order to prevent, if not completely prevent their abrasion, destruction, wear, then at least slow down these processes negative for the mechanism.

But over time, this can not be avoided, since the development of gaps in the interface still occurs. And the better the oil, the longer the service life of garden equipment will be. In addition, with the help of high-quality lubrication, the following positive phenomena occur:

  • better cooling of the engine and its parts, which prevents the occurrence of overheating and thermal shock;
  • guaranteed engine operation at high loads and with a long time period of continuous grass mowing;
  • safety against corrosion of internal engine parts during seasonal downtime is ensured.

Features of a four-stroke engine

Gasoline engines of lawn mowers are divided into two groups: two-stroke and four-stroke. Their difference in the method of oil filling is as follows:

  • the lubricant for two-stroke engines must be pre-mixed with gasoline in a separate container and in a certain ratio, mixed thoroughly, and after all this, poured into the fuel tank of the machine;
  • four-stroke grease and gasoline are not pre-mixed. these liquids are poured into separate tanks and work separately, each in its own system.

Based on this circumstance, the oil requirement is also special. It should retain its properties for a long period when, as for the lubricating composition of a two-stroke engine, the main quality criterion, in addition to the main properties, is the ability to burn without leaving a trace, without leaving carbon deposits.

Selection recommendations

It is best to lubricate 4-stroke engines of lawnmowers with a special oil designed for them in accordance with the ambient air temperatures under which the equipment will be operated. For instance, specialized grease of 10W40 and SAE30 grades are quite suitable for four-stroke mowers in their operational parameters, that can be used at ambient temperatures in the range from 5 to 45 degrees heat.

For lack of specialized oils, you can use other classes of oils used for automobiles. It can be brands SAE 15W40 and SAE 20W50, also used at positive temperatures, but only their threshold is 10 degrees lower than specialized ones (up to 35 degrees). And also for 90% of the number of available models of four-stroke lawn mowing units, SF oil will work.

A container with engine oil for a four-stroke lawn mower should be marked with the “4T” mark. Synthetic, semi-synthetic and mineral oils can be used. But most often they use semi-synthetic or mineral, since synthetic oil will be very expensive.

And in order not to guess which oil to pour into the engine of your model of mower, it is better to look at the instructions. It indicates the necessary type of oil, and the frequency of its replacement. It is recommended that only the types of oils specified by the manufacturer be used before the warranty repair expires in order to maintain the issued guarantees. And then to pick up something more affordable, but, of course, not inferior in quality to branded oils. You should not save on oil quality.

How often do you need to change grease?

As noted above, the manual for garden equipment with a 4-stroke engine must always indicate the frequency of oil change. But if there is no instruction, then they focus primarily on the number of hours that the equipment has worked (hours). Every 50-60 hours worked, you need to do an oil change in the engine.

However, in the case when the site is small and you can process it in no more than one hour, it is unlikely that the lawnmower will work even half an hour from the norm for the entire spring-summer season, unless you rent it out to neighbors. Then the oil must be replaced when preserving equipment in the fall before the winter period.

Change of oil

Replacing the lubricant in the engine of a lawn mower is not such a complicated operation as, for example, changing the oil in a car. Everything is much simpler here. The operation algorithm is as follows.

  1. Prepare enough fresh oil to replace. Usually, no more than 0.6 liters of oil is poured into the lubrication system of many lawn mowers.
  2. Start the unit and let it idle for several minutes to warm up the oil so that it becomes more liquid. This contributes to better drainage.
  3. Switch off the engine and place an empty container under the drain hole from the engine crankcase to collect the used oil.
  4. Unscrew the drain plug and allow all oil to drain. It is recommended to tilt the device (if possible or appropriate) towards the drain.
  5. Screw the plug into place and move the machine to a level area.
  6. Open the filling hole on the oil tank and fill it to the required level, which is controlled by the dipstick.
  7. Tighten the cork of the tank.

What kind of oil should not be added?

Grease intended for two-stroke counterparts must not be poured into a four-stroke engine of a lawn mower (the labels “2T” are put on the labels of oil containers for such engines). However, this cannot be done and vice versa. In addition, it is unacceptable to fill in the liquid that was stored in plastic bottles from under drinking water.

See the next video for how to change the oil in a four-stroke engine.