Adjustment And Repair Of A Trimmer Carburetor

The trimmer does not belong to the sophisticated household appliances, so most of its failures are mechanical and are quite successfully eliminated with their own hands. Even if the engine fails of severe reasons. damage to the piston ring, for example, repair comes down to replacing the part.
But even with a relatively simple design, such a device part, such as a carburetor, needs to be adjusted.

Principle of operation:

A carburetor is a power system module that mixes fuel oil and air before it enters the engine cylinders. Depending on the tool and its mode of operation, mixing and feeding are adjusted accordingly.
The mechanism of a trimmer carburetor is the same for almost all cases. It belongs to the category of float devices. The latter provides stable parameters of the finished mixtures.

The principle of operation of the module is as follows:

  • Air enters the body of the tube with an air damper. The latter increases or decreases the air flow depending on its position.
  • In the area where the opening for supplying gasoline is formed, the tube has a narrowing. a diffuser. Here the flow rate increases.
  • Fuel from the float chamber through the jet is fed into the tube. The level of the float determines the amount of fuel supplied. Since the pressure in the chamber is normal, and the tube is low due to the greater rarefaction of air, gasoline is sucked through the jet.
  • Accelerated air flow picks up the fuel and sprays it, forming an air-fuel mixture of the desired density.
  • The mixture is sucked into the cylinder through the pipeline.

The more open the air damper in the tube, the higher the density of the air flow, and, therefore, more fuel enters the cylinder. Setting the carburetor Trimmer reduced to the installation of such a ratio of valves, in which the density of the fuel mixture becomes optimal.

Signs of unbalance.

Debugging of the carburetor must be made in the manufacture of the device. As a rule, the need to adjust the fuel supply with their own hands, the owners will find out only after fairly serious damage, in the process of repairing which, the module was removed and, for example, cleaned.

Signs of a failure in the settings are the following:

  • It starts, but the engine immediately stalls. because the engine can only work when a certain amount of gas is supplied if the fuel supply is too poor, that is, the feed channel is blocked, the engine will stop;
  • too much fuel consumption, a lot of exhaust gases. the result of incomplete combustion of the mixture. In this case, on the contrary, there is too much fuel, and the mixture turns out to be excessively dense.

The carburetor Trimmer Stihl, Makita, Husqvarna and others are configured using the adjusting screws. Sometimes the reason for the breakdown of work is a violation of fixation. due to vibration or damage to the protective cap. Such a breakdown can be detected just by trying to turn the screw slightly: if the fixation is not rigid, you should check the setting.

Adjusting the carburetor Trimmer do it yourself.

Setting up the module does not apply to repair, and replacement of parts is not required. In this case, repair kit carburetor Trimmer not needed.

Three screws are provided for debugging:

  • L. is regulated first, as it is responsible for fuel delivery at low revs;
  • H. he is responsible for the supply of gasoline at high speeds, as well as fuel consumption and temperature;
  • T. use it to debug idle.

There are options, as a rule, it is the carburetor of the Chinese trimmer when there is only one screw left to debug the case. to adjust the idle speed. It does not mean that the module is configured automatically. it means that even such a repair as debugging will be difficult.

  1. The module is set up only when the engine is warm: for this, the device is pre-turned on for 10 minutes. If at idle the mowing head rotates, then debugging is started immediately: turn the screw T counterclockwise until the rotation stops.
  2. Adjustment begins with the screw L. The screw rotates to the right and left until it is found such a position at which the idle speed does not become maximum.
  3. Then turn the screw ¼ turn counterclockwise. It will be it’s working position.
  4. Idling should be adjusted by turning it counterclockwise to increase the number of revolutions and clockwise to decrease it. Its debugging is to achieve a mode in which a sufficient number of revolutions are performed before the start of rotation of the mowing head. In this case, the engine must operate stably at different positions.
  5. The position of the screw L is determined to last. at maximum speed, the trimmer should not work for more than 10 seconds. The throttle opens, the screw rotates clockwise, very slowly, until a decrease in the number of revolutions is found by ear.
  6. Then also slowly the screw rotates counterclockwise until the motor starts to malfunction. After that, the screw is turned back clockwise until the engine again works normally.

If there is a tonometer, and if the recommended rpm values ​​are indicated in the product passport, the correction can be made more accurate, focusing not on hearing, but the readings of the instrument.