How much oil to put in your lawnmower

How much oil should I put in my lawnmower??

as a rule, the ratio of oil to petrol for a well-known chainsaw manufacturer is 1:40 or 1:50, which means 1 part oil to, say, 40 parts petrol. Now the arithmetic: 1 liter of petrol = 1000 ml of petrol, divide by 40 and you get 25ml of oil.

At the beginning of work with the tool there is always the question of how much oil to add to gasoline for a chainsaw or grass trimmer. It’s important to remember that for two-stroke engines the ratio is 1:50, i.e. е. 100 ml of oil for every 5 liters of fuel.

Fuel mix for two-stroke engines

Grass trimmers, which are equipped with a two-stroke motor, do not have a separate system designed to supply oil for the purpose of lubricating the rubbing parts. For this reason it is not necessary to fill such devices with pure gasoline, but with a mixture of fuel and motor oil. The last one should be specially designed for two-stroke engines. The use of automotive engine fluid will lead to premature engine failure.

Preparation of fuel mixture for two-roller engines

To fuel a lawn mower with a two-stroke engine you need gasoline AI-92. Using AI-95 may cause engine overheating and uneven machine performance. Mix petrol with oil in the proportion 50:1, where 50 is fuel and 1 is oil. It turns out that 20 ml of oil is needed per 1 liter of fuel.

If the engine is worn or the tool works with a high load, the proportion is 25:1. If there is not enough lubricant, the cylinder walls and piston surface will be scuffed. The piston ring will be destroyed and the engine will jam as a result. Too much is not that critical, but it can lead to fouling. This will harden the piston ring, and thus reduce the engine’s power output.

Oil and gasoline proportions for the fuel mixture

What is the difference between oils for different types of engines?

The different working principle of the oil system requires different lubricants with different properties and characteristics.

the oil in four-stroke engines lasts the whole season, but in two-stroke engines it lubricates the parts and then burns off in the cylinder, which also affects the requirements.


According to the principle of operation, the four-stroke power unit is completely identical to car internal combustion engines.

That is why requirements for lubricating oil are the same as for conventional motor oil for high-speed automobile engines.

The main parameter of the lubricant for four-stroke engines is viscosity, which describes how fluid the oil will be at operating temperature, and the parameter is denoted by the letter “W” and the numbers before it and after it.

The figures before the letter describe the minimum negative temperature at which it retains its lubricity, but this parameter is not relevant for trimmers, because it is not used during frost.

Numbers after the letter describe viscosity at operating temperature. Lubricant normally used in four-stroke trimmers is 5W30 or 5W40.

Another relatively important parameter of oil for four-stroke motors is the type of lubricant, that is:

How to Change Lawn Mower Oil

Mineral oil is made by thermal distillation of crude oil and heavy oil products. It is cheap, but has mediocre lubricating properties and low resistance to high temperatures.

Synthetic oil is made from the various gases that flow out of the ground with the oil. It is much more expensive, but has considerably better lubricating ability and resistance to high temperatures. Semi-synthetics are a mixture of both.

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However, base oils of any type have extremely mediocre characteristics, so they are modified with various additives (additives) that change the properties of the finished product.

over, the oil requirements depend on the characteristics of the motor and its working conditions, but the trimmer engines work in much more comfortable conditions than automotive, so they are suitable oil, designed for any engine. For this reason, the containers with lubricant for trimmers do not indicate API class, that is, compliance for certain car engines.


Since oil for these engines works for only a few moments, after which it burns up in the cylinder, it is not required to have the same durability that is typical of the lubricant in four-stroke engines.

In addition, it should have a higher lubricating ability, because such oil goes to the bearing being highly diluted with gasoline.

Since all two-stroke gardening equipment engines operate in approximately the same conditions, there are no viscosity grades or classes of oil.

Two-stroke oil is fine for a grass trimmer, even if the packaging or container says it’s for the following two-stroke units:

An important condition is also a complete combustion in the cylinder, otherwise the grass trimmer will strongly pollute the environment, and the smell of its exhaust will be extremely unpleasant.

This is why an improperly formulated fuel mixture produces a thick, dark or bluish exhaust with a pungent, unpleasant odor. The same effect occurs when operating the machine with a faulty or out-of-tune engine/carburetor, as well as when over-boosting heavily.

How to use?

Lawn mowers mainly mow young, small grass on lawns and relatively flat clearings, but sometimes tall grass, weeds, bushes and even sloping meadows need mowing.

Even when mowing young grass, the correct sequence of operations must be followed, this will extend the life of the mower parts and reduce the physical strain on the operator.

All the steps you take when mowing can be broken down into:

  • getting ready to mow;
  • Selecting the operating mode;
  • straight-line movement;
  • turns;
  • stopping;
  • emptying the grass catcher;
  • Finishing work;
  • Lawn mower maintenance.

Preparing for mowing

This operation is especially important after a long break or after the mower has been in heavy use for a long time.

Preparation for mowing includes:

  • visual inspection of mower for visible defects, including loose bolts or nuts;
  • checking the oil level in the engine and topping it up or replacing it if necessary;
  • checking the condition of the belt, gearbox and blade, followed by maintenance, i.e. replacing, repairing, sharpening or lubricating if necessary;
  • Checking condition of all controls and lubricating/maintaining them, if necessary;
  • checking the gasoline level, and topping it up if necessary;
  • adjusting the collapsible handle for the operator’s height.

All of these procedures are described in detail in the instruction manual, so you should read this document carefully, and always keep it handy in case of any abnormal situations.

How much oil does it take to fill a lawnmower and how to change

In addition, on mowers where wheels are bolted to the frame, make sure that the wheels are properly secured and rotate freely, and if necessary secure or lubricate them.

much, your, lawnmower

Selecting work mode

Once you’ve prepared for mowing and brought the mower to the place of mowing, it’s time to select the correct cutting height and adjust the cutting height and dispose of the cuttings in the desired way.

On most models the mowing height is centrally adjusted, so you just move the lever to the desired position, but on some mowers the adjustment is made on each wheel individually.

It increases time spent on the procedure, but allows you to set the blade at a certain angle, which is useful when you work on difficult terrain.

Each mowing and ejection method choice is described in the instruction manual, therefore it is necessary to read this document carefully, as the choice of one or another method depends on mower design and is not always applicable even to devices made by one manufacturer.

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Straight movement

Straight-line movement of non-self-propelled machines does not cause any particular difficulties, because the operator pushes them at the most comfortable speed for him. The situation is different with self-propelled mowers, because their driving speed depends on the rotational speed of the engine crankshaft and the transmission ratio.

On single gear mowers the driving speed is regulated by changing the engine revolution speed, however for quality cutting the grass the crankshaft speed should not go below 2,5-2,8 thousand rpm, which is just a little less than maximum mowing speed.

If the shaft rotates slower, the blade will not be able to cut the grass efficiently and evenly. This is why mowers with variators or multi-speed hydrostatic transmissions must first be driven in the right gear for optimum ground speed, and only then.

On any self-propelled lawnmower to start moving forward push the appropriate bracket on the folding handle.


The mower cannot turn by itself, therefore the operator always has to physically push the mower forward.

For smaller grass areas with a larger turning radius (5 metres or more) turn the crank slowly to the opposite side at every turn.

However, if you have to turn in small spaces or in areas with high grass, you must first press the crank to raise the front wheels and only then turn the machine to the desired angle.

If you don’t lift the front wheels, you will have to exert a lot of effort because this creates a noticeable resistance to sideways movement.

In addition, on self-propelled mowers, the drive bracket must be released before starting the maneuver so that the drive wheels are not connected to the engine during the turn. If you do not do this and turn while driving, the load on the transmission will increase sharply and reduce its service life.


If it is necessary to stop briefly (for a few seconds, for example, to wipe sweat from the forehead), it is enough to stop pushing the non-self-propelled machine forward or to release the corresponding bracket of the self-propelled machine.

However, if the stop for 20 seconds or more, you need to release the bracket connecting blades and use the gas pedal to reduce the speed of the engine shaft to idle (900-1300 rpm, depends on the characteristics of the engine).

This will reduce fuel consumption and extend the life of the engine. If stopping for a minute or more, it is advisable to stop the engine as well, so that it does not waste its life unnecessarily.

Emptying the grass catcher

Some mower models are equipped with a grass catcher, that is, a container in which all cut and shredded grass is collected.

Requirements for lawnmower oil

Engines in small agricultural machinery are different from those in cars, so the lubricant must also be different. Do not fill the mower with a mixture designed for machines or motorcycles: it could cause damage. Even if there are no malfunctions, the lawnmower is likely to start working worse: a liquid not designed for this type of equipment will not be able to cope well with its functions. That’s why it’s recommended to use special oils designed for gardening equipment.

How to fill a petrol lawnmower?

For filling use clean unleaded gasoline that has been stored for no more than a week in a clean container with no oil residue.

It is necessary to fill up with fuel using a watering can or a special nozzle put on the canister to avoid spilling.

much, your, lawnmower

After all, spilled fuel is a serious fire hazard, as well as giving off an unpleasant odor and getting your hands or clothes dirty.

It is forbidden to fill the tank completely, because during operation the engine generates a lot of heat, some of which reaches the tank and heats its content, even if only slightly. This leads to increased fuel evaporation and higher pressure inside the tank, which also leads to increased pressure inside the fuel system.

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If this happens, the fuel-air mixture entering the cylinder will be richer, which means that the fuel it contains will not burn completely but will burn in the engine head and its muffler, which will reduce the life of these parts.

Before pouring fuel it is necessary to carefully read the instruction manual gasoline lawnmower, because it specifies the maximum level of fuel, which should not be exceeded.

In order to fill up the fuel, you need to do the following:

much, your, lawnmower
  • Stop the engine if the machine has previously mowed grass, then wait 5-10 minutes for the engine and its surroundings to cool down (if the mower has just been delivered to the place of work, this point does not need to be done)
  • clean the fuel tank cap, as well as the surrounding area from grass clippings or dust with a clean rag;
  • unscrew the cap and set it aside;
  • Using a watering can or a special nozzle on the canister, pour fuel into the tank;
  • put on and then wrap the cap;
  • wipe the cap, filler neck and tank with a clean, dry cloth.

What to pay attention to when choosing an oil?

When selecting oil for your lawnmower, you need to pay attention to the manufacturer of the product. It is necessary to give preference to that brand, which is specified in the instruction to technique. A large number of manufacturers of such equipment produce their own oils. these are to be used. They have a positive effect on serviceability and service life of the equipment. When choosing an oil, pay attention to the general lubricant characteristics given in the instruction manual. Do not use the first fuel you see, no matter whether it is a self-propelled or a petrol lawnmower. Do not buy the most expensive lubricant, it may not fit to a particular model. There is no one-size-fits-all option.

It is recommended to change the oil every 50-60 hours of mower operation


The large box that the lawnmower is packed in will not fit in the backseat of a sedan car. And the weight of the machine together with the package is not insignificant, more than 35 kg.

The following parts and accessories are included with the lawnmower:

  • Grass box consisting of a lid and two basket halves
  • The plastic part is the side ejection block
  • Plastic part. mulching kit
  • Two guides: for the engine and lawnmower separately

The result of calculating the fuel mixture:

To measure the right amount of oil in milliliters more conveniently, use a medical syringe of larger volume, it is inexpensive, sold at any drugstore. Or use any measuring container with graduations.

Our calculator will help you calculate the right proportion to fuel any power tool, e.g.: boat motor, chainsaw, grass trimmer, lawn mower, etc.д. In other words you can independently and for free calculate the correct gasoline to oil ratio for two-stroke engines. Mixing instructions on the photo below.

Before you start the calculation, especially read the operator’s manual and ask for the following information: capacities, fuel mix ratio. This data will be the starting point for the correct calculation.

For your convenience you can print out the result by clicking “Print” icon. We will be glad to receive your constructive Комментарии и мнения владельцев and feedback on our service.

Note that the power tool has a run-in period and the gasoline/oil ratio is different than recommended.

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