Lawn Mower Does Not Develop Speed

Why the motor isn’t picking up speed: from simple to complex

At the very beginning, we will consider simpler and more obvious faults. The set of revolutions during driving is strongly influenced by the feed efficiency, timeliness of ignition and the usefulness of combustion, as well as the composition of the fuel-air mixture.

A common reason when the engine does not pick up speed (injector, carburetor, diesel, gas car) is problems in the ignition system, as well as in the air and fuel supply systems. Experts point out the following:

  1. Heavy contamination of the air filter reduces the ability of air to penetrate the filter element, as a result of which the engine becomes uneven, the unit loses power and does not pick up speed. Also, a common cause of problems with the air supply can be the fact that a foreign object (rags, plastic bag, etc.) may accidentally become in the air filter housing.
  2. You should also pay attention to the suction of excess air at the intake as a result of various defects in the intake system. The problem can appear both unexpectedly and gradually progress. Note that the motor usually does not pick up speed in the event of a strong air leak. The fact is that in the composition of the fuel-air mixture, the normal ratio of air to fuel in such a situation deviates significantly from the norm. The mixture is very lean (a lot of air and a minimum of fuel). On such a charge, the engine starts, but does not gain momentum while driving, and also works intermittently.
  3. A similar picture can be observed when the required amount of fuel is not supplied to the unit. The culprit may be the fuel filter, which can also become very clogged. Note that there may be no problems with starting the engine, since there is enough fuel for the XX mode. In parallel with this, while driving, the car may jerk, react to pressing the gas pedal with a long delay, when speeding up, there may be dips or the unit may not spin above any mark on the tachometer.
  4. A dirty filter mesh of a gasoline pump can lead to similar symptoms. Deposits from the fuel tank tend to accumulate on the specified filter over time. As a result, the fuel pressure in the system becomes insufficient, the pump performance drops, and the motor itself is not able to operate normally in different modes. It often happens when the engine picks up speed and stalls precisely because of a clogged grid.

Now let’s talk about problems that may require certain knowledge, skills and equipment for diagnosis, as well as be a reason for a visit to a car service. To begin with, this list of faults usually includes those when the engine does not pick up speed due to the failure of any element of the ECM, ignition system, power supply, etc. In other words, we are no longer talking about consumables (candles, wires, filters, pipes), but about parts. In parallel with this, it should be considered whether the breakdown occurred unexpectedly or the malfunction progressed gradually.

  • One of the reasons may be knocked down timing phases. Violations of the synchronous operation of the gas distribution mechanism relative to the intake and exhaust strokes lead to the fact that the intake and exhaust valves do not open in time. The malfunction occurs as a result of errors when replacing the timing belt, if the specified timing belt has jumped one tooth or more teeth. Also, the cause may be incorrectly adjusted valves (the problem does not manifest itself sharply), various malfunctions in the systems for changing the valve timing, breakdown of the timing chain drive, etc.
  • Unexpected breakdowns include the failure of the ignition module, as well as malfunctioning of the ignition coils. In this case, cylinder misfires begin, the engine troit and loses its ability to pick up speed normally.
  • In situations with engine speed, the power supply of the injection nozzles should be checked. If there are problems with the wiring, then the control signal is not supplied to the injector or is intermittently received. As a result, the injector does not open in a timely manner, misfires occur in one or more cylinders, the engine does not pick up the required speed and loses power.
  • A fuel pump or fuel injection pump on diesel engines may fail. This malfunction usually does not occur immediately (unless the electrical wiring to the pump is damaged). Much more often, the drop in pump performance is gradual. Sooner or later, the pump will start pumping fuel very weakly, the pressure will be enough only for operation in the XX mode. An increase in load and speed will lead to the fact that the engine may stall under load, not spin up, etc.
  • In some cases, severe contamination of the injector itself leads to similar results. Driving on poor quality fuel, as well as ignoring the necessary injector cleaning procedure every 30-40 thousand kilometers traveled may mean that the performance of one or more fuel injectors has dropped significantly.
  • The engine speed can also be affected by the state of the EGR system, the throughput of the catalyst or diesel particulate filter. As for the second case, exhaust gas evacuation worsens through a clogged catalyst, the engine literally suffocates and is not able to gain normal speed.
  • In parallel, it is necessary to check various sensors of the electronic engine management system. Their incorrect operation can affect the composition of the mixture, that is, the amount of fuel and air supplied to the internal combustion engine. These sensors include DPDZ, DMRV and a number of others.

Frequent malfunction: the engine does not pick up speed and what should the driver do

If the engine stopped gaining speed, then the first step is to analyze when and how it manifested itself. In other words, the unit stopped spinning unexpectedly, or the problem with a set of revolutions gradually progressed. You should also pay attention to the presence or absence of other symptoms.

The fact is that the failure of a previously serviceable engine to gain speed after any repair or other manipulations may simply be the result of assembly errors, an unconnected sensor, etc. In such cases, the malfunction can be determined faster and more accurately after an independent inspection or immediate return of the vehicle to the service where the car was previously repaired.

Why the engine is not picking up speed well

During the operation of a gasoline or diesel engine, the driver may be faced with the fact that when the gas is pressed, the engine does not pick up speed. Note that after installing LPG equipment on a car, such a problem often arises when the engine on gas does not pick up speed, although the car runs normally on gasoline. Malfunctions of various kinds can cover both fairly simple things, and indicate the need for serious repair of the internal combustion engine. Next, we will consider why the diesel engine does not pick up speed or the gasoline engine refuses to spin up.

Lawn Mower Does Not Develop Speed

What is the result

Considering that there are a lot of reasons for problems with a set of revolutions on a modern car, it is optimal to immediately connect the car to diagnostic equipment (scanner) to search for possible errors. This is especially necessary when the engine does not pick up speed and the check on the dashboard is lit.

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Such failures are associated with a software failure in the operation of an electronic device. The ECU mistakenly assumes low speed (for example 2-3 thousand rpm) for the so-called cutoff speed and stops the fuel supply. In other words, the conditional protection against exceeding the permissible number of maximum engine speed is triggered prematurely.

Finally, I would like to add that timely cleaning of the injector, replacement of spark plugs and ignition wires, filters and filter elements of the fuel pump, cleaning the throttle valve, correct throttle adjustment and a number of other service procedures will allow you to get maximum power from your internal combustion engine. As for cars with LPG equipment, not only the engine power and its gas revolutions, but also the overall service life of the power unit will depend on the correct installation and adjustment, as well as on the timely replacement of filters and maintenance of other elements of gas equipment.

Failure in the fuel circulation system

Failure to properly circulate fuel on the trimmer will also result in the mower not picking up speed. This can be due to the following main reasons:

  • Air leaks, which are caused by cracks in the hoses;
  • Clogging of the gasoline pump, which occurred due to the use of low-quality fuel or due to the formation of sediment at the bottom of the tank and getting it into the system;
  • Dirty muffler or catalyst.

To fix the problems considered, you need to do the following yourself:

  • Go over the gas pump, removing dirt;
  • Replace pipes and hoses through which fuel circulates;
  • Clean the muffler and the mesh on it;
  • To install a new catalyst, which will be expensive due to the precious metal content.

All the work on troubleshooting the fuel circulation system can be done independently. But it should be done carefully so as not to lose parts, or after assembling the braid there are no extra ones left.

Low quality fuels

The trimmer does not develop revs if filled with low quality fuel. For this reason, the engine may not start at all or work in jerks, changing the speed of rotation of the knife or line.

To independently determine the quality of the gasoline used, perform the following steps.

  1. The candles are removed with a special key.
  2. Examine their working contacts for the presence of a red brick plaque: if there is one, then the fuel used contains significant inclusions of additives.

If a deposit is found, it is necessary to drain the fuel poured into the tank and replace it with a quality one. The lawn mower used must be filled only with the brands of gasoline specified by the manufacturers in the operating instructions. It is also imperative to clean the candles from plaque before reinstalling.

Possible causes of a problem with electric streamers

When using the trimmer, on which the electric motor is installed, problems with a set of revolutions also occur. But they are caused by completely different malfunctions, compared to fuel streamers. The electric motor does not develop the required rotation speed in such cases:

  • If the voltage in the supply network is lower than the rated value for the electric motor by more than 10%;
  • In case of malfunctions in the soft start system (if this unit is installed);
  • When there are problems with the brush assembly;

Electric scythe brush unit

  • In case of burning of the engine windings;
  • If wedging of rotating parts occurs.

To eliminate the problem with the voltage, you need to check its value with a multimeter or tester in the outlet from which the electric power is taken. If it is less than the minimum permissible value, then to increase it, you will need to turn off all electrical appliances or install a stabilizer.

To repair the soft starter, you will need to have the appropriate knowledge in electronics, so it is better to contact a service center. There they will decide on its maintainability or the need for replacement. You can check the button yourself or find the block diagram and try to figure it out.

Soft starter block

The brushes may wear out and contact will be lost as a result, causing the motor to stall. The brushes are easy to replace. The features of the process are determined by the lawn mower used. Along the way, you will also need to clean all contacting surfaces.

If the windings are burnt, if you continue to mow the grass or bushes, the electric motor will quickly burn out. This will be accompanied by the appearance of a burning smell, up to the melting of individual parts. You will need to replace the electric motor.

Wedging of rotating parts occurs for various reasons. To identify and eliminate them, you will need to sort out the drive unit. There are models in which the number of revolutions is automatically adjusted depending on the load, increasing with its increase; at idle speed, the rotation speed decreases.

Shown is an algorithm of actions to identify the most common reasons why the trimmer is not gaining the required speed:

Engine problems

If everything is in order with the fuel, filters and spark plug, then the next source could be a gasoline engine. He may have the following mechanical failures:

  • Carburetor problems;
  • Engine drive train problems.

There is a small cable in the carburetor section. It can subside and lead to the problem in question. Therefore, when dealing with the carburetor, you should first check the condition of the cable, and, if necessary, tighten (but not to the limit). The main thing is not to overdo it with a stretch, so that it does not crack under load.

Carburetor cables

Then you need to check the operating settings of the carburetor, which must correspond to the parameters given in the instructions. If they are installed correctly, but there is no desired effect, then the part should be disassembled, rinsed, cleaned, pumped through all its strokes and assembled back. The carburetor itself must be free of mechanical damage.

In the event that adjusting or replacing the carburetor does not give the desired result, it is necessary to clean the drive mechanism and lubricate the cable located inside it with oil.

Engine problems can be fixed with your own hands if you have the required skills, but it is better to use the services of a service center for this. Its specialists will carry out a comprehensive diagnosis of the trimmer and establish the exact cause of the drop in speed.

Common Causes of Low Speed ​​Lawn Mowers

The problem, when the lawn mower does not pick up speed, occurs mainly with gasoline units. This affects the equipment of various models, for example, Husqvarna, Champion, Stihl.

Some of the structural elements with which problems may be associated are available for visual inspection, and to check the functioning of the remaining units, the lawn mower will need to be disassembled.

Spark plug problems

Spark plugs become dirty and worn over time with continuous use. To check this, they are removed and inspected for carbon deposits. The problem can be eliminated in two ways: if possible, restore the old candle, or simply install a new one in its place.

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In the first case, they act like this:

  • Unscrew and wipe the candle off the fuel;
  • Dry it without calcining;
  • Using a file or fine sandpaper, remove carbon deposits from the candle and check the gap between the electrodes (should be 1 mm);
  • Collect trimmer;
  • Start a lawn mower.

If the candle does not emit a spark after recovery manipulations at the desired distance between the electrodes, then you will need to check the quality of the connections of the electrical circuit elements of the device. When the wires are in complete order, you will need to unambiguously install a new part.

Replacing candles is a simple process that is cheap, and if you can restore old ones, it is generally free. For work, you only need a candle wrench and a file.

How to check the muffler

To check the muffler, it must be removed from the chainsaw. To do this, using an 8 mm head, two fastening nuts are unscrewed and the part is removed.

Important: after the muffler is removed, it is necessary to check the integrity of the gaskets between it and the cylinder, since very often they stick and break when the muffler is removed.

You can clean the part mechanically, using screwdrivers or a knitting needle, and then blow it thoroughly with compressed air. The seat on the muffler can be cleaned with sandpaper to remove burnt-on gasket parts.

Install the muffler in reverse order.

Important: when tightening the nuts of the muffler, do not pull the nuts excessively, since the threads on the screws can be torn off.

The second reason why the engine of a Stihl chainsaw can reduce power and not develop rpm is a blockage in the fuel system. As a rule, the first place to start looking for a blockage is the fuel filter.

The reasons why the Stihl 180 does not develop momentum

The Stihl 180 chainsaw does not develop revs or after you release the gas trigger, it continues to work without dropping the revs. These problems are common enough. Let’s try to understand the reasons that result in the occurrence of such malfunctions. Also in this article we will consider how to diagnose if the chainsaw does not pull.

Why the chainsaw won’t slow down

There may be several reasons why the chainsaw does not slow down:

  • Broken throttle spring;
  • Jamming the gas trigger;
  • The throttle rod is bent;
  • Lost throttle shaft corkscrew causing it to wedge.

It is not difficult to solve all these problems, you need to conduct a careful inspection and determine the exact cause, and then change the faulty part. As a rule, if the chainsaw picks up speed well, idles and has normal power, then the problem with the fact that it does not slow down is purely mechanical. And finding and eliminating a mechanical malfunction is much easier than identifying and stopping air leakage in the crankcase of a chainsaw.

Stihl 180 does not develop momentum, the most common reason can be seen below. In it, the owner of the Stihl chainsaw ms 180 tells his story of solving the problem with a loss of power.

Checking the fuel filter

The fuel filter is installed in the tank of the Stihl 180 chainsaw, and it is not very convenient to pull it out. To facilitate the process, you can take a small piece of aluminum wire and bend it at the end, then use it to hook the fuel hose and remove it, along with the filter, from the tank. To check the filter, it is necessary to blow into it, if air does not pass, then the reason has been found, and the filter needs to be replaced.

If the filter is clean, check the fuel hose for clogging. To check, it is necessary to disconnect it from the carburetor and, with the air filter removed, blow into it. If a blockage is found, the hose can be cleaned mechanically, using a wire, and then blown out with compressed air.

Depressurization of the carburetor and blockage of the nozzle

Sometimes, when the screws securing the carburetor cover are loosened or the gaskets have become unusable, there may also be a loss of power on the chainsaw, in order to eliminate the likelihood of this malfunction, it is necessary to check the integrity of the gaskets and the tightening of the screws on the carburetor covers. To do this, you need to remove it from the engine (the algorithm is described above) and disassemble. Defective gaskets must be replaced using spare ones from the repair kit for the Stihl MC 180 carburetor.

In the case when a complete check of the fuel supply and exhaust system has been carried out, but there are no results. It is necessary to check the main fuel injector valve. To check, it is necessary to knock it out of the carburetor body. All work should take place according to the following algorithm:

  1. The carburetor is removed from the chainsaw.
  2. The four screws securing the cover with the compensator are loosened, after which the cover can be removed.
  3. The carburetor is installed on a wooden lining, after which it is knocked out into the internal cavity of the carburetor using a bolt with a diameter of no more than eight millimeters and a length of 50.
  4. Next, you need to pick up a small hose, the inner diameter of which corresponds to or slightly less than the outer diameter of the nozzle and put it on the nozzle.
  5. The next step is to blow inside the hose. If it is blown in only one direction, the nozzle is in good order, if it blows in both directions or does not blow at all, then the valve must be replaced.

All of the above actions should help in eliminating the malfunction associated with the fact that the chainsaw is not gaining momentum, otherwise, a full diagnosis in the manufacturer’s service center will help.

During the engine running-in period (this is approximately the work of the trimmer on 2-3 tanks), the amount of oil can be increased. For example, mix it with gasoline in a 30: 1 ratio.

A small amount of oil mixed with gasoline leads to increased wear of the cylinder-piston group. An excess of oil in the mixture, although not so fatal, is also harmful. Coking of the piston rings, rapid formation of carbon deposits in the combustion chamber, and a drop in engine power may occur. In addition, the muffler mesh screen is coked. Therefore, some users (after the end of the warranty period for the trimmer) recommend dismantling it.

Gasoline used in the AI ​​92 lawn mower. The brand of gasoline is precisely specified in the operating instructions. You should not try to force the engine by pouring 95th gasoline into it. This can cause overheating, erratic trimmer operation and breakage.

It is not recommended to leave fuel in the trimmer tank during extended shutdowns. It is better to end the working day with the entire mixture completely exhausted. If this is not done, then, since the gasoline will evaporate from the engine overnight, and a thin film of oil will remain, the carburetor jets may become clogged. This will cause difficulty the next time you start the engine.

It is also necessary to observe safety precautions when storing fuel. Many people pour gasoline into a plastic water bottle. Is it worth doing this?

How to properly replace the spark plug?

The order of work is as follows:

  • Stop the engine and wait for it to cool down.
  • Disconnect the high voltage wire from the spark plug.
  • Unscrew the part using a special wrench.
  • Inspect the spark plug for replacement. The part changes if it is defective, heavily soiled, has a crack on the case.
  • Check the gap between the electrodes. Its size should be 0.6 mm.
  • Tighten the new spark plug inserted into the engine with a wrench.
  • Install the high-voltage wire to the center electrode of the candle.
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As you can see, there is nothing super complicated in this procedure.

A new spark plug for a two-stroke internal combustion engine of a gasoline streamer is installed to replace the old part that is out of order

What to do if the engine won’t start?

If the lawn mower fails to start, the first step is to check the availability of fuel in the tank and its quality. To refuel the tool, it is recommended to use high-quality gasoline purchased at gas stations, the grade of which must be at least AI-92. Saving on cheap fuel can lead to a breakdown of the cylinder-piston group, the repair of which can take a third of the cost of the lawn mower itself

It is equally important and correct to prepare the fuel mixture from gasoline and oil. The proportional ratio of these components of the mixture is indicated by the manufacturer in the manual

It is not necessary to prepare the fuel mixture in large volumes, since its properties are lost during long storage. Better to use a fresh mix.

When preparing the fuel mixture, pour oil into gasoline using a medical syringe, which allows you to accurately observe the required proportion of components

A dirty fuel filter in the tank can also prevent the mowers from running. Therefore, if problems arise with starting the motor, check the condition of the filter. Replace the filter if necessary. It is forbidden to leave the inlet pipe without a fuel filter.

The air filter also needs to be checked. When contaminated, the part is removed, washed in gasoline in the field and put in place. In the country or at home, the filter can be washed in water using detergents. After that, the filter is rinsed, wrung out and dried. The dried filter is moistened with a small amount of oil used to prepare the fuel mixture. Excess oil is removed by squeezing the filter with your hands. Then the part is installed in place. The removed cover is put back and secured with screws.

The air filter, washed in a fuel mixture, wrung out and dried, is installed in place in a plastic case and closed with a lid

You can look at how this procedure is done in more detail at:

If all of the above procedures are carried out, and the engine does not start, then adjust its idle speed by tightening the carburetor screw

In the posted at the beginning of the article, attention is paid to this issue

So, in order:

  1. Place the tool on its side with the air filter at the top. This arrangement of the chainsaw ensures that the fuel mixture hits the bottom of the carburetor. The engine will start on the first attempt if you remove the air filter and pour a few drops of the mixture into the carburetor before starting, then reinstall the dismantled parts. Method tested in practice.
  2. If the first tip doesn’t work, then the problem is most likely in the spark plug. In this case, unscrew the spark plug and check its functionality, and also dry the combustion chamber. Replace the candle that does not show signs of life.
  3. If the spark plug is in good working order, the filters are clean and the fuel mixture is fresh, then you can use the universal method of starting the engine. Close the carburetor choke and pull the starter handle once. Then open the throttle and pull the starter 2-3 more times. Repeat the procedure three to five times. The engine will definitely start.

Some people pull the handle with such force that they have to repair the starter with their own hands. This is only possible if the cable breaks or the cable handle breaks. In other cases, it is recommended to replace the starter. This unit is sold assembled.

Tips for choosing

In accordance with current statistics, it is gasoline mower models that are in greatest demand. This is largely due to their mobility and functionality. However, when choosing a specific model of equipment, it is necessary to take into account a number of other parameters. In situations like this, it is useful to compare lawn mowers with other types of trimmers.

Electrical devices are connected to a household network with a voltage of 220 V. Such machines do not pollute the air due to the absence of exhaust gases. No less important points will be the minimum noise level and the relatively low weight. At the same time, the area to be treated is significantly limited by the length of the carriers used.

Cordless models are by far the least common grass trimmer. The electric motor of these mowers is powered not from the mains, but from the battery, which ensures maximum mobility. However, the operating time of the equipment is limited by the battery charge and averages 35-45 minutes. Another important point is the relatively high cost of battery models.

When choosing a specific model of a gasoline trimmer, you must take into account its technical characteristics. So, low-power devices are equipped with reels with fishing line

On more resourceful and powerful models, knives and cutters can be used as cutting elements.

Features and best models

The mower of the Stihl company deserves a special mention, which is distinguished by its own versatility, reliability and ease of operation. The company’s specialists have created many varieties of braids, with different features and applications.

For example, the lawn mower range is designed for mowing grass in large areas. For this, a self-propelled wheel system was developed, with the help of which it became possible to take care of a large territory without spending a lot of time and effort. A lawn mower is perfect for decorating shrubs, giving them a certain artistic image and texture. Lawn Mower Does Not Develop RPM Reason And if you need a lawn mower for tall grass and uneven areas, then follow this link and get full information on the selection of this type of equipment.

If you need a more subtle approach to grass trimming, for example, near flower beds or between trees, then the gasoline trimmer, designed for accuracy and precision, is perfect for this task. The company’s specialists have foreseen all the nuances and possible difficulties when working with braids, so they equipped them with nylon strings that prevent mechanical damage to trees.

A special AutoCut trimmer head is also used to ensure the normal functionality of the petrol trimmer string knives. This article will tell you about the of petrol hand-held lawn mowers and trimmers, it will also help you make the right purchase, which you will not regret.

There are two types of these mowers: amateur and professional models, designed to solve problems of a certain complexity. The first category includes models FS 38, FS 45, FS 55, etc. The features and differences of these tools are in the motor power (from 0.9 to 1.2 HP depending on the configuration) and the volume of the tank (approximately 0, 34 l).

The professional trimmers include Stihl FS 130 and FS 250. Let’s consider the characteristics and properties using the example of several mowers, in particular FS 38, FS 70 and FS 130.

See device features on.

For some reason, the Stihl electric scythe does not develop its full power

When using the electric trimmer, speed problems can also occur. The reasons here are completely different than those of fuel braids.

You can fix problems yourself

The trimmer does not develop the required power because:

  • The voltage in the network is below the required minimum for the device more than 10%;
  • There was a failure in the soft start (if such a system is available);
  • There was a malfunction of the brush assembly;
  • The motor winding is burnt;
  • Rotating parts sometimes jam.