Husqvarna Trimmer Carburetor Adjustment
Lawn mowers carburetor device
The standard design of any gasoline trimmer necessarily includes a fuel system, the basis of which is the action of a standard carburetor. Its design and initial principle of operation are almost the same for all lawn mowers, regardless of their design features and purpose.
The lawn mowers carburetor consists of an all-metal aluminum housing that protects the internal components of the unit from moisture, small debris and dust. In the lower part of the body there is a built-in diffuser, the second name of which is “Venturi nozzle”. The main function of this standard part is to supply air in the amount required by the fuel unit to enrich the fuel. A diffuser works according to a simple principle: the smaller its diameter becomes, the more intensively the air is sucked in. This is due to the fact that in the area of the smallest diameter, the level of air vacuum becomes maximum.
The upper part of the built-in factory diffuser is pre-equipped with fuel pipes through which, under the influence of air, the fuel mixture is drawn in. The rest of the carburetor parts: standard adjusting screws and a fuel pump, can be located both inside and outside the carburetor.
The device of the carburetor of lawn mowers includes a throttle valve, the main task of which is to regulate the volume of intake air. The larger the amount of air, the higher the rated power of the trimmer power unit. Another function of the damper is to facilitate cold starting of the engine. If this is the first time the mower is started after a long period of inactivity, the shutter must be closed. Immediately after starting the engine, the part must be opened, otherwise the internal combustion engine will stall.
The carburetor for the trimmer is equipped with an impulse channel that connects the internal cavity of the engine crankcase with the impulse chamber of the pump. The piston located in the cylinder of the engine creates a reciprocating motion, which leads to gradual changes in pressure inside the crankcase. At the same time, the membrane is set in motion. Thus, the action of the pump is fully synchronized with the operation of the power unit.
The diaphragm of the standard carburetor takes an active part in the suction of fuel. It enters the fuel unit through the fitting. The fuel then flows through the built-in intake and exhaust valves, then through the strainer and fuel pipe. The fuel then flows next to the needle and gradually fills the chamber equipped with the control diaphragm.
The standard carburetor trim valve is connected to the diaphragm using a lever. Below the built-in membrane is a cavity into which air is sucked in through a special opening.
The lawn mower carburetor works on this principle in stages. This ensures continuous operation of the fuel unit and uninterrupted fuel supply to the cylinder of the standard power unit.
When adjusting the carburetor of the household trimmer is required?
Adjust the built-in trimmer carburetor when:
- Running in a new engine, during which 4 to 5 liters of fuel mixture were used;
- Sudden changes in weather;
- Changes in air pressure. For example, when the lawn mower is often used in mountainous areas;
- Long simple trimmer;
- Intensive growth of loads on the power unit of lawn mowers;
- Arbitrary unscrewing of the built-in carburetor adjusting screws. This causes increased vibration of the internal combustion engine;
- Changes in the quality of the components of the fuel mixture;
- Pouring fuel with a carburetor, resulting in an increase in fuel consumption;
- The regular appearance of a thick layer of resinous deposits and carbon deposits on the surface of the electrodes of a standard trimmer spark plug;
- Starting the engine and its arbitrary shutdown or slow set of revolutions;
- Lack of fuel flow into the cylinder of the power unit;
- Increase in the volume of emitted waste gases.
The lack of timely adjustment of the carburetor threatens serious damage to the trimmer, up to the complete failure of its factory engine.
Carburetor for trimmer: device, do it yourself setting
Stable and efficient operation of a household trimmer largely depends on the quality of the fuel used by the operator. The filled fuel mixture must be enriched with air. A built-in carburetor is responsible for this in the basic device of the lawn mower. This knot is one of the main elements of the streamer, so the operator must constantly monitor its serviceability and settings. Otherwise, the trimmer will lose its performance and may completely fail.
DIY lawn mowers carburetor adjustment
Periodic adjustment of the trimmer carburetor should be performed on a serviced and fully serviceable power unit. Before starting the procedure, the operator must thoroughly rinse the internal combustion engine parts and inspect its CPG for burrs or other defects. In addition, you will need to clean or change the spark plug, as well as rinse the filter elements in the lawn mower design.
The lawn mower engine must be running under a certain load when adjusting the carburetor. It is best to install a cord of the appropriate diameter or cutting knives on the trimmer.
After installing the cutting elements, the operator should start the internal combustion engine of the trimmer and leave it to work for about 10 minutes. If, during the operation of the power unit at idle, it was noticed that the cord or knife rotated, then it is necessary to reduce the speed generated by the motor. To do this, turn the lower adjuster, often marked with the letter “T”, to the left, until the installed cutter comes to a complete stop.
Further configuration of the fuel assembly is as follows:
- The “L” regulator, located on the right, is responsible for enriching the fuel mixture with air when the engine is running at low speeds. The position of this screw must be adjusted first. To do this, the operator will need to achieve maximum engine speed when idling. To do this, turn the screw “L” one by one to the right or left. Once the maximum speed is reached, the screw will need to be turned 1/2 turn to the left;
- The “T” or “LA” screw is required to adjust the idle speed. While turning it to the left, the speed of the power unit will decrease, and when turning to the right, it will accordingly increase;
- The regulator “H”, provided on the left, is responsible for enriching the fuel mixture with air when the internal combustion engine trimmer is running at high rpm. This screw is also needed to adjust the engine power and the amount of fuel consumed. Its position is adjusted by turning the screw to the right or left side until the maximum permissible engine speed is reached. After that, the screw “H” will need to be turned 1/2 turn to the left.
Performing these steps one by one will allow you to correctly configure the fuel trimmer assembly, without the risk of exceeding the permissible load on its main working mechanisms.
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