The Lawn Mower Does Not Pick Up Speed At Full Throttle

Not enough fuel to feed and run the chainsaw at full power

If the chainsaw stalls when gas is added, it means that the fuel is not supplied in sufficient quantities for the full operation of the chainsaw. This may be due to both clogging of the carburetor (its jet) and contamination of the filter itself (fuel). Remember that only professionals should check the first node, but you can clean the second one yourself.

The main elements of chainsaws

Before starting to delve into the issues of breakdowns and tool repairs, let’s first figure out what the chainsaw itself consists of. First of all, I would like to note that this tool belongs to the category of technology, the operation of which directly depends directly on the internal combustion engine.

It is also important that chainsaws are equipped with an engine with one cylinder, and the work of which is carried out on such kind of fuel as gasoline. It is worth noting that, despite the similarity with other tools, it does not have a gearbox. And it is replaced by a kind of single-stage chain transmission, through which the movement of the chain itself (saw) is made.

In fact, a chainsaw is a fairly simple design, but this does not prevent it from being reliable, practical and fully capable of providing direct uninterrupted and cyclical operation even in rather difficult conditions. This tool consists of a huge range of certain elements “vital” for its correct and productive work. This is a carburetor, a direct chain tensioner, a tire complete with a chain and other elements.

To simplify your choice, we have compiled for you a rating of chainsaws in terms of reliability.

If you have a limited budget, then read the article about Russian chainsaw manufacturers.

Wrong fuel

An important fact is that for the trouble-free operation of the tool, it is necessary to be quite careful about the fuel itself. Since if this kind of mixture is not prepared correctly, then most chainsaws will simply not start. Therefore, not every owner will guess to look for the cause of the breakdown in the fuel. That is why, in order for your tool to always work correctly, you need to use exclusively high-quality gasoline for the mixture.

Otherwise, overexposure of the mixture directly in the canister will lead to the fact that it will lose all of its octane properties and this will lead to significant problems with the instrument.

Why does the chainsaw stall when you give gas when pressed, and does not start under load at idle

There are often cases when the owners of chainsaws are faced with their breakdown and it does not matter which model of this kind of equipment, since the nature of the breakdowns is almost the same for everyone. Well, the chainsaw has stalled and what’s next? Undoubtedly, you can refer the technique to specialized services that will repair your “iron friend” for a fee. But as the saying goes: why pay more?

After all, you can personally disassemble the tool and repair it, since the breakdown may be insignificant, and in the service you will pay a lot for this. But naturally, in order to bring the instrument back to life yourself, you need to be able to understand the reasons for its breakdown and how to troubleshoot it. So let’s learn! In this article, you can find answers to questions regarding situations when the instrument simply stalls after directly pressing the gas. So let’s get started.

Filter dirty

In order to solve this kind of problem, all you have to do is disconnect the (fuel) hose from the carburetor and pay attention to whether the fuel is leaking from it. Since if the mixture flows in a full stream, this means that the breather is not contaminated, but if on the contrary, the cause of the breakdown has been found.

Insufficient chain lubrication prevents starting and the saw does not develop speed

Many people ask the question: why does the chainsaw stall when I press the gas? The answer may also lie in insufficient chain lubrication (see Chainsaw chain oil), since the oil line may leak, or the direct channels may simply be clogged. That is why pay attention to the chain, because if it is dry, then, without delay, start cleaning the channels that supply oil directly to the tool tire. After that, inspect in detail the parts where the oil pump fittings are connected to the pipes. But if you notice that the oil leaks at the joints, or found cracks on the pipes themselves, then in the first case, seal the leak points with a sealant, and the pipes will have to be replaced.

Silencer as the cause of the saw stalling under load

Here’s another reason why the chainsaw stalls when you press the gas. the muffler. It is this part that can interfere with the full operation of the tool in cases where it is contaminated directly with exhaust resinous deposits. To do this, you just need to clean it.

Why does the chainsaw immediately stall and thrash when the gas is pressed

Chainsaws are fairly reliable and simple designs. Therefore, if you properly care for them and handle them based on the manufacturer’s recommendations, then they fail well, very rarely and various kinds of breakdowns are quickly eliminated. But if you are faced with this situation and want to personally repair your tool without resorting to the help of professionals, then delve into the information provided below.

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In fact, it is unambiguously and precisely impossible to determine the reason why the instrument does not start or stalls when you press the gas, since there are a lot of factors affecting this. But do not forget that, starting from the fact that the chainsaw is equipped with a simple two-stroke engine, conditions such as lubrication, fuel, spark and air are important for its effective performance.

Therefore, the carburetor is directly involved in the preparation of the fuel-air mixture, the filter cleans the air from dust, the ignition unit and the spark plug create a spark, and the gasoline contains grease.

That is why it is necessary to search for the causes of this kind of failure in a sequential order, starting directly from the simple ones and gradually moving on to the complex ones. And this is an important factor in the correct repair, since the person who, without thinking, begins to disassemble the carburetor, brings it to risk. Since this kind of unit must be repaired or adjusted directly in special workshops (read about carburetor adjustment).

There is no spark and the chainsaw does not pick up speed

The chainsaw stalls when you press the gas due to the fact that there is no spark. This can happen when there is no good contact between the tip of the candle and the wire (high voltage). However, if this kind of connection works correctly, but there is still no spark, then the whole reason is the ignition unit (electronic). It is important to note that parts of this kind cannot be repaired, so they can only be replaced.

Do not forget that by examining the spark plug, you can get significant information regarding the breakdown of the chainsaw. Since if its surface is dry, then the reason for this is the cylinder, which is not directly supplied with fuel. That is why you will have to check the entire range of its presentation step by step. If the candle is covered with black carbon, then this means that the carburetor is not working properly, that is, it either supplies a lot of fuel or pours oil directly into gasoline.

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.

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:

  • 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 that a foreign object (rags, plastic bag, etc.) may accidentally become in the air filter housing.
  • 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 turns out to be very “poor” (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.
  • 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.
  • 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 diagnostics, 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 details. 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 during the timing belt replacement, if the specified timing belt has jumped one 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, check the power supply of the injector nozzles. 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 on time, misfires occur in one or more cylinders, the engine does not pick up the required speed and loses power.
  • The 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 cleaning procedure for the injectors 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 pick up 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. Such sensors include DPDZ, DMRV and a number of others.
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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 momentum after carrying out any repairs 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.

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.

Such failures are associated with a software failure in the operation of an electronic device. The ECU mistakenly takes low speed (for example 2-3 thousand rpm) for the speed of the so-called “cut-off” 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 the maximum power from your internal combustion engine. As for vehicles 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.


This mechanism is an important part of the petrol trimmer. In order for the carburetor to work properly, several conditions must be met:

  • Disassemble and clean it from time to time;
  • Adjust the idle speed according to the instructions;
  • Refer to the help of the wizard when adjusting.

In the event of a breakdown of this unit, you can do its repair yourself, but only if you have certain knowledge.

One of the reasons for poor carburetor performance is a loose cable. To eliminate the problem, you first need to disassemble the entire assembly, and then, after thoroughly washing all the parts, lubricate and tighten the cable, but not very much, so as not to stretch.

Dirty air or fuel filter

If the lawn mower is not gaining momentum, the reasons may lie in the contamination of the filter element: air or fuel.

When the air filter becomes clogged, there is a lack of oxygen in the combustion chamber, so the fuel is not fully produced, which prevents the development of the required speed and power.

To check if the reason is the air filter, you need to remove it and turn it on. If the lawnmower is still not picking up speed, it’s not the cause. So you should check the fuel filter element. Here everything is the same, only gasoline acts as oxygen. If this filter is damaged, there will be a lack of fuel, which slows down the development of speed.

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 there is such a system);
  • There is a malfunction of the brush assembly;
  • The motor winding is burnt;
  • Rotating parts sometimes jam.

To adjust the voltage, you should first check its power. If it does not meet the standards, you should increase it with a stabilizer.

Repair of the soft start system is carried out only in the service center.

Note! When the brushes wear out, you just need to replace them. When installing new ones, it is recommended to clean all surfaces with which they come in contact.

To adjust the voltage, you should first check the power.

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If the motor windings are burning, you need to change the electric motor.

Jamming of rotation parts can occur for various reasons. To eliminate them, you should revise the entire drive assembly.

Note! The latter problem may arise with another unit of this company. the Stihl secateurs, and sharpening the disc with scissors will be its solution.

Fuel system

The functioning of the fuel system is of great importance for the trouble-free operation of the petrol trimmer. Gasoline passes through all its assemblies and parts, so they must be cleaned regularly. In addition, only high quality fuel must be used. To prepare a combustible mixture in a two-stroke engine, motor vehicle oil cannot be used, since it has insufficient qualities.

Troubleshooting methods

The first three reasons are fairly easy to eliminate. If the matter is in the mixture, it is necessary to pour out the old fuel from the tank, prepare a new emulsion from high-quality gasoline and engine oil (if your engine requires a mixture) and pour it into the fuel tank. If the trimmer is running on pure gasoline, it’s still easier.

In the second case, it is necessary to carefully free the trimmer parts from the wound grass.

The last reason a lawn mower doesn’t work properly will require a little more knowledge and skill from you.

In order to properly adjust the carburetor for lawn mowers, a specific procedure must be followed. First, clean the air filter thoroughly. The easiest way is to rinse it (it is advisable to pour water over the filter regularly after 9-10 hours of operation).

After that, in the diagram of your trimmer, which is in the operating instructions for the device, find the adjustment screws. Usually there are three of them: the first is responsible for the fuel supply, the second is for idling, and the third is designed to limit the number of maximum engine speed.

Next, turn on the unit and wait for the engine to warm up.

Tighten the first (fuel mixture) adjusting screw slowly. Catch the moment when the motor starts to stall, and turn the propeller back 45 degrees. If you didn’t have time and the motor stalled, the screw should be turned 90 degrees. Open the throttle and watch the revs increase. Next, slowly unscrew the screw (each turn is the same 45 degrees) until the moment when, at full throttle, the engine begins to firmly give out maximum revolutions.

The second screw, as mentioned above, controls the engine idle speed. By loosening it, you decrease the number of revolutions, while twisting it, you increase it. The screw needs to be adjusted so that the motor runs reliably at low revs. For better starting, speed up the engine slightly. At the same time, make sure that the motor rotates several tens of times before starting the movement of the knives / line reel. If the engine starts poorly, tighten the screw a little.

After you have adjusted the first two screws, test the operation of the unit at maximum engine speed. If necessary, you can limit it (maximum). this will protect the motor from “boiling”. To do this, you need to tackle the third screw. Unscrew the locking nut until the adjusting screw can be safely turned. To increase the maximum number of revolutions, the screw must be loosened, to decrease. on the contrary, tighten. Fix the position of the screw with a nut. Test the motor again.

Remember that carburetor adjustment is not a final procedure. During the operation of lawn mowers, you will most likely have to tinker with it more than once, because an unbalanced carburetor means both increased fuel consumption and a quick failure of the candles, not to mention a decrease in the power and performance of the device.


The engine is the most important part of any machine. There are several reasons for ICE breakdowns:

  • Incorrect proportions of oil with fuel (for two-stroke);
  • Old fuel mixture;
  • Wear and destruction of the piston ring;
  • Scratch marks on the cylinder and piston;
  • Wearing the device.

All this leads to the fact that the engine either does not start, or stalls.

Diagnostics and elimination of problems of electric motors

Trimmer malfunctions can be as follows:

  • Violation of insulation or cable breakage;
  • Malfunctions in the area of ​​the cutting tool;
  • Damaged socket or plug.

To deal with these breakdowns, you do not need to disassemble the entire apparatus.

In case of serious engine problems, you will have to disassemble it. To do this, you need to unscrew a few screws. Having gained access to the parts of the motor, you need to carry out the following actions:

  • Check the degree of wear of the brushes. unsuitable parts will need to be replaced with new ones;
  • Ring the motor winding. the resistance must be high;
  • Check the stator and rotor. to test the rotor winding with a multimeter, measure the resistance: large deviations from the norm indicate a malfunction, the absence of resistance on the stator winding also indicates a breakdown (the stator case is diagnosed in a similar way).

Low rp problems are common with cheap trimmers. However, with improper maintenance, this also affects hand mowers such as the Huter, Patriot 3055, Echo.

technical issues

Technical problems with lawn mowers mainly occur in the fuel supply and ignition systems. You can deal with them yourself.

The Lawn Mower Does Not Pick Up Speed At Full Throttle
  • When the hand mower won’t start or stalls, the problem could be with the spark plug. Dark carbon deposits indicate poor carburetor adjustment and poor gasoline quality.
  • A clogged fuel hose may be the cause of the trimmer not working correctly. Filters are also often clogged.
  • Another internal problem. the muffler is covered with carbon deposits. From this, the trimmer speed drops sharply. Exit. you need to clean the muffler.

The reasons

Trimmers are reliable and durable (provided they are properly maintained, of course). Most often, malfunctions occur due to contamination of structural elements.

If the motor of your lawn mower does not start, does not pick up speed, does not reach the power you need, or suddenly stalls, the reason may be:

  • Poor quality fuel (fuel mixture), it may be in long-term storage or in non-compliance with the recipe for preparing the mixture;
  • Grass is wrapped around the shaft of the fishing line / knife;
  • Clogged air filter / muffler;
  • Carburettor imbalance.