How to Start a Gasoline Grass Trimmer

Running in the brushcutter engine. Peculiarities of the lawnmower running-in

It should be noted that a gasoline grass trimmer is very easy to operate. It’s enough to see how other users use this machine to start using it to its fullest potential. The performance of basic technical functions is intuitive and does not require any difficulty in practice. Proper running in of the gasoline grass trimmer is also not difficult. Not only that, there is almost no difference between the devices of the household and professional categories.

The key difference is the type of motor. On the technique for professionals, it is more powerful and gives more speed. The two-stroke engine is more often used in domestic models. Four-stroke units are more reliable and provide more power, so they are suitable for special conditions, difficult and overgrown areas.

In addition, you should take into account whether there is a cutting attachment in the delivery set.

Pre-starting preparations

So, let’s start with getting ready for work. So how do you get your lawnmower ready to use?

First of all, reassemble it if it is disassembled. Securely fasten the split rod in the latches. Carefully check the fixation of the cutting equipment, especially if it is a knife or saw blade. Gasoline grass trimmers tend to be extremely powerful and their cutting attachment rotation speeds are fantastic. Therefore, a poorly fixed blade, firstly, can injure the worker, and, secondly, causes additional vibration in the tool, which can lead to its breakage.

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Gasoline models are most often equipped with a two-stroke engine, so they require the preparation of the fuel mixture. What is its purpose? Since such motors do not have a crankcase and a separate system for oil lubrication, this role is performed directly by the fuel mixture.

It is prepared in certain proportions and for one filling. Do not immediately dilute several liters, with “reserve”, as the composition should always be fresh.

Prepare the refueling mixture

When starting the unit after the winter season, or staying in a cold room, it is necessary to check the tank for residual fuel. If residue is found, it is imperative that the mixture be drained.

Features of the refueling procedure:

  • The dressing can be as a ready-to-use mixture as well as a mix for self-preparation.
  • When filling four-stroke engines it is not necessary to prepare the fuel mixture.
  • The units cooperate better with oils having SAE-30 index.
  • It is not recommended to change the oil of synthetic type with mineral type and vice versa.
  • Chinese, Japanese, American gasoline lawnmower works better on A-92 fuel. European models accept high octane numbers well.
  • Be sure to monitor the level of the mixture, the best option. 2-3 centimeters below the edge of the fuel tanks.

The first thing to do is to check the presence and quality of fuel

Do not understand why the lawnmower does not start, then first make sure that there is fuel in the tank. Often beginners forget that it is necessary to pause periodically to refuel the tool with a gasoline-oil mixture. If the mower’s tank is empty, of course it won’t start, no matter how many times you try.

If there is fuel in the tank, but it is impossible to start the engine of the tool, then do not rush to disassemble the carburetor. Make sure that the grass trimmer‘s engine is started correctly, as indicated in the manual. If the start-up is performed according to the instructions, then it is important to consider the following points:

  • Do not just use quality gasoline with the highest octane rating, but exactly the brand recommended by the manufacturer. And it is not always gasoline AI-95. If you do not know what gasoline to use for the lawnmower, then choose AI-92
  • Oil should be special. for two-stroke engines. If the lawnmower has a four-stroke motor, it should be filled with pure gasoline without stirring with oil. On the quality of oil for the grass trimmer engine should not be economized, as well as on gasoline. After all, the quality of the fuel used determines the operational life of the motor
  • Correct preparation of the fuel mixture in the gasoline trimmer. Observations show that most mowers only control the process of preparing oil with gasoline for the grass trimmer for the first time. The more experience the mower has, the less attention is paid to the process of mixing gasoline and oil for a two-stroke engine. The ratio of petrol and oil should be as recommended by the manufacturer. Typically, the ratio is 25 to 1, that is, 1 liter of gasoline needs 40 ml of two-stroke oil (engine oil for the car and the more waste can not be used)
  • Proper fuel mixture storage. It often happens that after the fuel mixture is prepared, it stands for a long time for more than 2 weeks. Do not keep the ready mix of gasoline and oil for a long time, because it causes the oil to precipitate, and thus the properties of both oil products are lost. Even stirring the mixture thoroughly after it has been stored for a long time is not a reason for continuing to use it. That is why it is not recommended to prepare more than 2 liters of mix at a time

Make sure that all of the above points are met, and only then can you proceed to check the condition of the spark plug. The grass trimmer does not start for a variety of reasons, and most of them can be identified by yourself. It is simply not practical to disassemble the carburetor if the engine cannot be started. The next step in troubleshooting is to check the condition of the spark plug.

Reasons why the lawnmower may not start

No matter what technology requires careful maintenance and compliance with operating rules. As if the tool works when checked in the store after delivery to the house or a few days of operation does not start. Before calling for service, you may try to solve the problem without the help of others. The causes of malfunction in gasoline and electronic lawnmowers are different.

The petrol lawnmower may not start for the following reasons:

  • First of all, before starting the engine, you need to check the fuel in the tank. pump up a small amount of gasoline will make the system choke, but you should not fill the tank to the brim. It’s a good idea to check the fuel level in the tank before starting the engine. If you leave the mower for winter storage, fuel must be drained because gasoline tends to evaporate. Filling fuel is done with a funnel. Before the accidental drying of spilled gasoline on the mower parts do not start the engine, to avoid the ignition of flammable water.
  • Not infrequently, the engine lawnmower does not start because the user does not know how to start it correctly. Before starting the lever set the maximum speed, and then pump gasoline into the carburetor with a primer. Pull the starter cord gently and then pull sharply.
  • After trying to start the lawnmower without success, it might be a good idea to change the spark plug. This is often the cause. If there is no spare spark plug available and the old one is covered with heavy soot, it should be cleaned with a fine-grained emery paper.
  • clogging of the air filter leads to bad fuel mixture and the engine starts to choke or does not start. It is easy to fix the problem by washing the removed filter in clean gasoline and then letting it air dry. The air filter has to be flushed every 25 hours even if the lawnmower does not choke.
  • Immediately after starting the engine may stall because of a jammed piston or crankshaft. After unscrewing the spark plug with the starter cord, pump the engine several times. Moving parts can work themselves out and the problem is solved.
  • Low oil level in the crankcase can be the reason that the engine does not start.


Lawn mowers have air-cooled engines, so clean cooling fins (fan) ensure the quality of operation and protect against overheating. To clean them, you sometimes have to remove some of the outer parts of the engine. It is a good idea to clean with compressed air, but you can also use a simple soft brush.

The engine must be filled only with quality fuel, this affects its performance, service life, and hence saves your budget. Drain the gasoline before winter, but it is better to work out all the old gasoline, then no plaque will form. After the gasoline is gone, turn the starter, then all the valves will close. Fill them in the spring.

Change the oil and spark plugs periodically. Change the oil according to the term specified in the manual. Drain the old one and dispose of it, and pour in the new one, but only of the right grade and viscosity. Some motors have a drain at the bottom, and sometimes you have to turn the technique on its side. It’s best to drain the oil when the engine isn’t cooled, then it flows out faster and takes a lot of accumulated debris with it. Use oil up to the mark and don’t let any dirt in.

Change the plugs should be changed if they are worn, rusted, burned out. If you see encrustation or deposits on the spark plug, you may clean it or just put a new one on, set the proper gap (according to the manual) and tighten it carefully with a torque wrench.

Also do not forget to clean, and if necessary, change the fuel and air filters. The more dust in the operating areas, the more often you need to do it, and before winter it is obligatory.

Types of gasoline units for grass mowing

Today there is a wide variety of machines.

Professional lawn mowers have the following features:

  • The petrol mower engine starts differently. With a special key on the control panel, the starter starts the engine from the battery. With the help of a “twitch” the hand starting machine is started.
  • Different methods of processing the cuttings. Mowed grass is thrown directly on turf, used for mulching or collected in special container. The bag for grass collecting needs to be emptied at regular intervals.
  • Mowers with mulching mowers are equipped with either four-stroke or two-stroke engines. They differ in features of work cycle, power parameters.
  • Maneuverable self-propelled machines have high actual productivity, because the large mowing width parameters allow you to process vast areas per unit time. The manual self-propelled lawn mower is used successfully in the processing of flat land masses. The technique is equipped with a mechanism for wheel drive.
  • Gasoline-driven devices with front-wheel drive are needed on uneven terrain. They have an excellent rating. Aggregates with rear drive are used on the flat surface of land masses. Always relevant when processing a small lawn, overgrown with grass, design with rear-wheel drive.
  • The volume of the fuel tank of gasoline lawnmowers is important when choosing a model, if you have to treat a large area of turf with high grass and other vegetation. No refuelling needed.

How to choose a quality device

Today’s gardening equipment market offers a wide range of modern models. Structural and operational advantages of different models with mulching, which have a high rating, can be evaluated by users. What lawnmower is better. gasoline or electric? Review the models will help professionals. The service life of the equipment, the performance of the units largely depend on the brand, so it is better to study in advance the rating of manufacturers of such units.

Especially important is to pay attention to the engine. Its power and width should be chosen depending on how much lawn is to be processed. Making your choice, it is necessary to make a review of the models on the market. A catalog of different types of units is available in each showroom. It is important to accurately assess the size of the area, the amount of work. Continuous operation time depends on the power of the unit and the volume of the tank for the fuel mixture. Grass catcher box is easier to clean than mulching equipment. Such a machine has a high rating, in wet weather will not rust.

start, gasoline, grass, trimmer

Safety is of paramount importance when working with a machine. Greater manoeuvrability on mulching mowers with rear-mounted engine. You can significantly reduce the impact of vibrations on your hands by choosing models with soft-touch control handles. Self-made gasoline machine will help to solve the problem.

Gasoline grass trimmer stalls when idling

The engine of your brushcutter often shuts down when you reduce the engine speed and will not idle on restart. The main reasons of such failure can be clogged air filter or dirty carburetor.

The gasoline grass trimmer stops when idling

If the carburetor is not operating optimally, it may need to be flushed and re-set. Grass trimmer air filter clogging can be dealt with by placing it in a solution with an ordinary household detergent for several hours. If self-cleaning has not helped to cope with clogging, it is better to buy a new filter element in accordance with the manual.

After carrying out the measures, the user for a long time will not face the situation when the grass trimmer stalls at idle and functions only when the gas is supplied.

Lawn trimmer structure

Before repairing the device, it is necessary to understand what it consists of. There are many models of garden equipment of different brands: self-propelled, self-propelled. They are all positioned the same way. Construction components:

start, gasoline, grass, trimmer
  • Platform on wheels;
  • Gasoline engine (starter, carburetor, ignition and fuel system, air damper, filter, piston system, fuel tank.);
  • Handle;
  • Water jet nozzles;
  • Cutting elements (blades);
  • Grass box (container);
  • Fresh grass trimming section;
  • Buttons, control levers;
  • Body (aluminum, steel, plastic).

Let’s start the lawn mower running-in

After start-up, do not rush to run in the grass trimmer immediately. Allow 5 minutes for engine to warm up at idle speed. While it is warming up, adjust the airflow with the choke knob so that the line or blade bobbin does not rotate. Once the tool is warmed up, let’s open the air supply by moving the lever to the “ON” position and squeeze the throttle trigger 1/2 way for about 2030 seconds. Then release throttle and let the trimmer work for 30 to 40 seconds at idle. Continue in this mode for 10 15 minutes. Then turn off the gas and let it rest for 1520 minutes.

After the lawnmower has cooled down continue running-in the engine according to the previous scheme. Starting up the grass trimmer when it is hot is necessary with an open air flap. Try not to hold gas for a long time, because moving parts of the tool only rub against each other. Do not let the engine run for a long time at idle speed, as it can overheat.

The next step is the running-in of the gasoline lawnmower gearbox. To do this you need to choose an area with soft young grass. And last 510 minutes with 1/22/3 of full throttle. After that we make a break for 2025 minutes. Repeat this cycle 34 times.

Generally starting mower in accordance with described above algorithm may be done until fuel mixture in the tank is completely exhausted. After that the tool is ready for continuous work. During operation, check the temperature of the gearbox and motor. Do not overheat.

Use and care of your brushcutter (grass trimmer)

Engine. Keep the air filter clean (no dirt or shavings) and the foam filter dripping with oil. Check the fuel filter once a week and replace it if necessary, if the tool is used a lot. Check nuts and screws for tightness. before starting work. Clean the muffler (or muffler mesh) and plugs as necessary.

Cutting blades. Cutting edges must be well and correctly sharpened using the necessary templates and files (emery boards), observing the cutting angles depending on the type of disc. Double-sided blades should be turned 180° at regular intervals and worn evenly. Dull disc or disc with a bad or improper sharpening badly cuts, and thus overloads the engine, which leads to an accelerated reduction in its motor life.

Trimmer lines and trimmer heads. Use only straight line specially designed for trimmers. do not use wire or metal ropes! Use only a line of the same size as recommended by the machine manufacturer. Wind the bobbin tightly but not over the coils. Clean debris from mowing head and lubricate as needed. A worn or deformed brushcutter head can cause damage to the reducer and/or brushcutter shaft.

Corner gearbox. Clean off dirt as needed (such a “coat” prevents proper cooling of the gearbox) and apply Husqvarna or similar grease to the gearbox couple.

Protective guards. Never operate without the blade guard. danger to life and limb and may overload the brushcutter engine. For each type of cutting equipment, you should use only the blade guard provided by the manufacturer.

Self-repair brushcutter

It is necessary to note that it is not always possible to repair brushcutters yourself, but in most cases everyone is able to do small repairs.

If the grass trimmer motor is broken, and you are not an auto mechanic or electrician, it is better not to try to fix the mechanism. There is a good chance that you will not be able to reassemble it. There may be such problems: low compression in the engine, the engine is jammed, the carburetor is out of order. If these word combinations do not tell you anything, you should not repair brushcutter on the picture and intuition.

It should be noted that the maintenance and repair of a chainsaw and a brushcutter are similar in many ways.

start, gasoline, grass, trimmer

Trimmer for grass consists of a rod, a motor (sometimes on top or bottom), and mowing head with blades, various additional elements. What can be repaired by yourself??

air flap; 2. handle; 3. engine stop device; 4. throttle control lever;

limiter bracket; 6. rod; 7. cutting attachment protector;

1) If the on/off tumbler has blown, and you are familiar with simple wiring diagrams and are good with a soldering iron, solder and rosin, you can easily replace the tumbler with a new one. They are available in electrical and lighting stores.

2) If the wire restraint has fallen off the brushcutter head you can wrap it around the shaft with a piece of flexible copper or aluminum wire. It is also possible to make a new attachment from a strip of stainless steel.

3) If the trimmer line breaks on the cutter bar, nothing could be easier than replacing it yourself. You can, of course, just buy a head for brushcutter separately and replace it, but the line for the trimmer is one hundred percent cheaper. A 0.9 to 1.5 mm trimmer fishing line, nylon or kapron, is the best material. Measure the diameter of the line you are using at once, before it runs out completely. Thinner. can tear, thicker. causes overheating of the engine and unnecessary vibration. You need to disassemble the drum and wind the line for the trimmer manually, then assemble the drum.

4) If the bar breaks, it can also be repaired by wrapping and gluing it to wooden laths or iron staples.

5) If the engine is starting to vibrate and is running “rough”, you might need to lubricate your brushcutter. Any grass trimmer is easy to disassemble, it is recommended to lubricate it with technical oil at least once a year.

7) If the grass trimmer is equipped with plastic knives, and they are deformed for some reason, there is a way to replace them with metal ones. To do this you need some stainless steel blades. At home it is a bit difficult, but the situation can save a familiar turner, working at an industrial plant or factory. The blades are attached to the shaft with a sleeve with a washer. This modernization will lead to the fact that the trimmer will be possible to mow grass of any hardness. But caution when handling such a trimmer is worth increasing.

8) Engine does not start? In order to start the boiler, sometimes even when it is hot, it is necessary to close the choke completely to enrich the mixture. Check the gasoline intake, clean the spark plug, replace it if necessary.

Inspecting the gearbox of your lawnmower and lubricating it

Checking the gearbox before starting the gasoline grass trimmer should be done on a regular basis. Lack of lubricant or too little lubricant increases friction in the gear reducer, which operates at quite high RPM. As a result, overheating occurs and the gears. Gearbox in a brushcutter fails. Prevent the occurrence of such a breakdown during operation and helps regular inspection.

If you find, before starting the gasoline grass mower, insufficient lubrication in the gearbox or its absence in the housing is laid “LITOL. To do this, you need to unscrew the screw on the bend of the gear housing and fill it with 1-2 ml of LITOL.

Working with a gasoline trimmer for a long time, every 8-10 hours add grease to the boom gearbox.

Preparing the right fuel mixture

Before you start running in a new lawnmower engine, you also need to properly prepare the fuel mixture. As it is known for two-stroke engines it is prepared of a special two-stroke oil and gasoline, taken in certain ratios. To determine the recommended ratio, consult the instruction manual of your power tool or the lubricant label. You can learn the recommended fuel type and the recommended engine oil type from the manual.

Prepare fuel in small quantities, enough for one cut of grass. Use special plastic jerrycans for fuel, or separate glass or metal containers. It is better to apply oil with a syringe.

When getting ready to run in a new lawnmower many people have problems with fuel mixture. And the reason for that is the discrepancy in the tool manufacturer’s instructions and in the engine oil manufacturer’s instructions. The first ones recommend 1:25. The latter recommend 1:50. Who to trust?? What to do?

According to the experts’ opinion, if the manufacturers write the oil ratio 1:25 or 1:30 in the instructions to the brushcutter, it most probably means a cheap tool with bad cooling or a producer doesn’t know what kind of oil the consumer will add. But here it should be understood that an excess of lubricant does not affect the performance of the grass trimmer in the best way. Excess oil does not burn out completely when the engine is running. It cokes, clogs the cylinder and the piston.

What to do in this situation when running in a new tool? It is ideal to buy the oil that the mower manufacturer recommends. In the case of running-in engines when you cannot buy the recommended oil it is better to get a good Husqvarna two-stroke oil for the gasoline-powered tools of the same name. It’s not cheap, but it lasts a long time. You have to mix it as it is written in the instruction on the jar.

Remember, it’s best to use the proportion that the oil manufacturer gives. It’s better to find out by experiment if the oil mixing ratio is correct or not. If at the proportion recommended by the manufacturer of the grass trimmer, the engine is snotting oil and you can see leaks on it, then the proportion should be increased.

complex causes of lawn mower failure

If the step-by-step troubleshooting algorithm did not yield results, and your grasshopper still does not start or stalls, it is worth inspecting the carburetor and the engine itself. A clogged carburetor can be one of the causes of unstable operation of the tool. There are three main problems:

  • Clogged passages or jets. All this can be cleaned with special washes or with a powerful compressed air jet from a compressor. Do not use needles and wire, as the passage sections can be damaged;
  • Wear of carburetor gasket. The way out is to replace the failed gasket;
  • Leakage problems. To check this indicator, you can use an ordinary household tonometer, replacing it with a suitable pressure gauge. Watch the readings: if they do not change. everything is fine, and if the pressure begins to fall, it means that some part of the carburetor is defective. You have to find it and replace it with a new one.

If everything is okay with the carburetor, the gasoline grass trimmer may not start due to wear of the piston group. If you find chips, scratches, or scrapes on the piston or cylinder, replace them. Piston rings are subject to mandatory inspection. A slight play on the piston when rocking the connecting rod is an indication that the rings need changing. This procedure is best left to professional service.

How to use and store the lawn mower

To ensure that the lawnmower starts well in the future, it is necessary to ensure good storage and operating conditions:

  • During operation, carefully monitor the cooling system, carefully and timely clean the channels in the body, as well as the starter ribs;
  • If necessary, use solvents, kerosene or other cleaning agents for cleaning;
  • Do not clean tools while they are hot. leave them to cool down;
  • Always follow the operating instructions or you may overheat the engine;
  • if you do not plan to use the mower within the next month, the fuel mixture must be drained from the mower. к. Over time, it disintegrates into heavy fractions which will definitely clog the carburetor channels;
  • after draining the fuel let the trimmer run at idle until it stops, this will help remove the remaining mixture completely.

Do the following steps before winter storage:

  • completely disassemble the braid, rinse and clean all the parts you can;
  • Inspect parts for damage, and if necessary, repair misalignments, rips, bends, and any other malfunctions;
  • Pour enough oil into the gearbox and clean the air filter;
  • you can partially disassemble the motor, rinse, purge and lubricate all moving parts;
  • to lubricate the piston, unscrew the spark plug, raise the starter piston to its dead center, pour some oil into the spark plug hole and crank the crankshaft a couple of times;
  • if you are storing the mower out of the house, wrap the engine with an oiled rag.

Remember, the careful observance of the rules, will allow you to forget about the fact that the lawn mower starts badly for several seasons.