Trimmer Stalls When Pressing Gas Why

lawn mowing is a mobile high-performance tool for the refinement of household plots and surrounding areas. During long-term operation due to wear of parts or production defects, malfunctions arise that lead to the fact that the trimmer stalls or does not start. Since this tool is a rather complicated mechanism, there can be several reasons why the lawn mower stalls.

Trimmer Stalls When Pressing Gas Why

Why does the trimmer stall

There are two main ways to solve problems: transferring the braid to a specialized center or do it yourself. The first option is suitable for those who are ready to pay a “tidy” amount to restore the unit’s performance, and the second is for someone who has basic locksmithing skills and can independently understand the causes of breakdowns and how to fix them.

Currently, it is customary to classify breakdowns by which the lawn mowers stall into the following categories:

  • mechanical damage to the engine crankcase, cylinder piston group (CPG) malfunctions;
  • breakdowns associated with the supply of the fuel mixture (air filter, carburetor);
  • malfunctions due to damage to tubes, hoses, cables or the ignition circuit.

The mowing stalls when you press the gas

Lawn mowers gas key

Hole in the fuel cap (breather) trimmer

Lawn mowing fuel valve

With a similar problem, it is worth paying attention to the fuel valve, which, when clogged, ceases to normally allow the fuel mixture to pass through. The solution to this malfunction is to attenuate it with a suitable tool. In addition, the problem with the circulation of the fuel mixture may lie in the contamination of the valve. To do this, just blow it with a stream of compressed air.

lawn mowing stalls at high engine speeds

During operation, a situation arises when, when you press the fuel mixture supply key, the unit speed does not increase but decrease. A malfunction of this nature may be caused by:

Fuel Lawn Mowing Hoses with Filter

  • etching of atmospheric air into the combustion chamber;
  • problems with the circulation of the fuel mixture;
  • blockage of the breather in the cap of the fuel tank (cleaning the hole with a thin sewing needle);
  • incorrect carburetor adjustment.
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When air leaks during the operation of the internal combustion engine, it is necessary to check the tightness of the pipe connection and the integrity of the gaskets in the CPG. The problem with the circulation of the fuel mixture can be solved by eliminating blockages in the fuel pipes leading to the carburetor. If there is a vacuum in the tank and the fuel mixture does not enter the carburetor, it is enough to clean the breather with a thin needle and blow it with air.

The gas trimmer stalls idling

Often when the speed is reduced, the lawn mowing engine stalls and does not support idle when restarted. The main reasons for the occurrence of such a breakdown include pollution or deregulation of the carburetor, as well as clogging of the air filter.

Idle petrol trimmer stalls

If the carburetor is not optimally tuned, it must be cleaned and re-adjusted. The clogging of the trimmer’s air filter can be dealt with by placing it for several hours in a solution with ordinary household detergent. If self-cleaning did not help to cope with clogging, then it is better to purchase a new filter element in accordance with the instruction manual.

After the events, the user for a long time will not encounter a situation where the trimmer stalls at idle and only functions when gas is supplied.

Video: Trimmer Stalls When Pressing Gas Why


A spit that has a gasoline drive is a useful thing for owners of personal plots, lawns, and when the trimmer suddenly stalls, the work to clean the area from grass stops. The device itself is a rather complex mechanism, so there are many different reasons for its breakdowns. The most common problems are contained in the instruction manual. To know the reasons why the trimmer stalls, you should be able to effectively repair the device yourself.

What could break

Problems with the lawn mowing due to the fact that this device does not start are classified in a certain way by service technicians. They highlight malfunctions with the following nodes of the mechanism:

  • an engine in which the piston and bearings may wear out or fail, crack the crankcase;
  • fuel supply system, while it is possible clogging the filter or problems with the carburetor;
  • mechanical damage to wires, tubes, hoses;
  • ignition circuit.
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When you press the gas

If the lawn mowing stops when you press the gas, then the reasons may be as follows.

  1. The most common option is carb adjustment failure, which occurs with significant loads on the drive, after prolonged inactivity of the mechanism or when it is used in difficult conditions.
  2. Fuel valve clogging, which eliminate it by relaxation, as a result of which gasoline starts to flow normally through the system.
  3. Loosening and drooping of the cable in the carburetor. May also occur fuel hose extension up to its rupture caused by the action of a significant load.
  4. Clogged breather (check valve), as a result of which fuel does not enter the tank.

If the problem is related to the carburetor assembly, then it can be recognized by the appearance of vibrations of the lawn mowers.. When the hose bursts or the cable is stretched, these components are replaced.

At high speeds

When the braid stalls at high speeds, this is due to the following problems:

  • clogging or sticking of the valve located on the gas tank cover;
  • the carburetor is out of alignment under the influence of vibrations arising from the operation of the mechanism;
  • problems with the circulation of the fuel mixture;
  • air leaks;
  • fuel intake hose is cracked or loose.

Carburetor adjust, Based on the operating instructions for the trimmer. To adjust, it is often enough to loosen the tightening of its body. If there are problematic moments with the circulation of the fuel mixture, then it can gradually enter the carburetor. After its development, the engine stalls at high speeds.

At idle

At idle, common causes of trimmer stopping are the following:

  • contamination, misregistration or improperly adjusted carburetor adjustment;
  • clogged air filter;

Replacing the Lawn Mowers Air Filter

Trimmer air filter

  • reducing the speed of the gearbox when it is heated, which is a consequence of the use of an unsuitable fuel mixture;
  • throttle clogging;
  • air entering the system;
  • not enough fuel for lawn mowing.
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Right after wound up

The unit may stall immediately after start-up, if the carburettor is misregulated or has been incorrectly configured, this causes uneven fuel supply. The result of this is that the device begins to vibrate distinctly. To troubleshoot, the carburetor is reconfigured according to the instructions for the mechanism.

Also the engine stops when it happens valve clogging, supplying fuel. In such cases, it is simple enough to clean it. If the lawn mower first worked, but then immediately died out, then perhaps the fuel enters the carburetor assembly with some difficulty. The easing of the valve helps to solve the problem, which ensures free circulation of the mixture in the system.

A stop can also be called. air suction in the presence of mechanical damage to the hose (holes, cracks) producing fuel. In this case, add revolutions to the drive in order to quickly expel air bubbles from the system.

When heated

lawn mowing often stops when heated. At the same time, it starts, works “jerkily” and gradually stops. This process occurs when gas in the carburetor boils or a shutter in it is installed rotary, and not disk type. In the latter case, the item is changed.

It happens that the trimmer heats up if ignition wire damaged either a coil. In order for the device to start working normally, replace parts.

When opening the choke

It happens that the unit stalls when the air damper is opened, normally idling. This is due to air leaks in the system caused by the presence of fuel hose cracks or problems with oil seals. Also, the carburetor dosing system may malfunction, while the lawn mowing will stop after opening the damper.

Carburetor fuel hose

All possible reasons that the lawn mower stalls, and methods for their elimination are contained in the next video

There are many reasons for stopping the lawn mowing, but the most common problems in operation are related to its carburetor. They can occur in any cases. The most problematic option is when a serious breakdown occurs, and you will need to purchase new parts or change the lawn mower.