How to adjust the carburetor on a petrol cutter: device and procedure

Sometimes, for the good operation of a device, it is not required to repair one or another part, replace it, or worse, replace the device itself. Sometimes it is enough to understand the principle of its operation and configure it correctly. For example, a lawn mower's carburetor can be adjusted to avoid high fuel consumption or more serious problems.

Carburetor device gas cutters

A gasoline lawn mower, as the name suggests, is powered by an internal combustion engine that uses gasoline as fuel. In order for it to burn inside, air is required to form a reaction. The latter creates thermal energy, which then turns into mechanical energy.

A carburetor is used to supply fuel with air into the engine cylinder.

First, gasoline mixed with oil is transferred to the float chamber. There it continues its flow further, but when the required level is filled with fuel, the float rises, shutting off the fuel supply valve. The jet is a plug that prevents fuel from flowing out of the float chamber.

Gasoline flows into the mixing chamber, from above which air is supplied. The throttle blocks the access of fuel to enter the cylinder. When you press the mower pedal, it opens, and fuel is supplied inside, and the internal combustion engine picks up speed. The maximum throttle valve can rotate up to an angle of 90 degrees, which depends on the force of pressing the gas pedal. A vacuum is formed in the mixing chamber, a strong air flow mixes with the fuel and transfers it to the cylinder.

At low revs, an idle system is used, in which the throttle does not open completely, but partially.

The carburetor filter cleans the fuel from dust and other small elements, protecting the nozzles from their harmful effects. If they become clogged, the motor power will be noticeably reduced.

The task of the carburetor is to quickly direct the fuel to the cylinder with the help of air, mix it with oxygen, which allows gasoline to burn. The difference between an automobile carburetor and a trimmer is only in the presence of a membrane in the latter, which is used to suck gasoline from the tank.

How to understand that the carburetor of the brushcutter needs adjustment

This may be evidenced by the following signs:

1. Difficult starting of the engine, weak set of revolutions.
2. Increased fuel consumption.
3. The engine runs unstable, rpm jumps frequently.
4. There is a large amount of exhaust fumes.

Checking the spark plug can help determine if the carburetor is properly adjusted. First, we release it from the casing, disconnect the contacts from the igniter.

We clean the nest of the candle with a device that blows air. A compressor with a small tube is ideal for this purpose. Using a torque wrench, remove the spark plug.

After pouring a solvent for washing the threads into the socket of the spark plug, after a short period of time we unscrew the plug to the end. If the electrodes are blackthen this is carbon deposits that are associated with poor carburetor adjustment. If it is of a brick shade, then everything should be in order with the petrol cutter.

After a long period of inactivity, the tool also needs adjustment. For example, after winter.

It is also recommended to carry out the adjustment when changing the composition of the fuel mixture: oil or gasoline.

How to adjust a DIY lawn mower carburetor

First you need to prepare:

1. Flushing the engine can be carried out by draining the old oil and replacing it with a new one, but high base number, the ideal is the diesel option. You can also use mineral. You need to work with it for some time and the internal combustion engine must clear itself. If this option is not suitable, you can use a heavier and more expensive one. Remove the unit and rinse with a pressure washer. We completely disassemble it, put it in parts in a bath with chemistry.
2. Then you need to pull out the candle using the method described above., replace it with a new one. It is worth considering the candle precisely as a consumable that needs to be replaced in the event of a malfunction.
3. Next, you need to check how well the carburetor is attached to the cylinder-piston group.
4. The next step is to clean the air filter. To do this, you just need to blow it with compressed air, the best way is with a compressor.
5. The spindle holds cutting knives or a reel.
6. The adjusting springs are checked. They can be too tight and too thick to make accurate carburetor adjustments. If this is the case, then it will simply not be possible to configure it normally. To solve this problem, you need to purchase a new spring and insert it in place of the previous one.

Adjustment

Sequencing:

1. We start the engine. When you run it on XX knives should not rotate, if the opposite happens, then we reduce the idle speed.
2. We regulate screw L. He is responsible for the mixture at low revs. First, we scroll clockwise until it stops, then unscrew it 90 degrees counterclockwise. If gaps are found, we repeat this action, weakening it by 1/8, that is, by 45 degrees.
3. We regulate screw LA, the more common name is T. As the XX rpm increases, more air is added to the mixture. Power is lost. But if there is not enough air, the fuel is burned worse. We unscrew the screw so that it works perfectly at low speeds, while knives should not rotate. In the process of tuning, you need to feel the speed, it should work stably at XX.
4. We regulate screw Hwhich adjusts the mixture at high revs. To identify their maximum number, we use a tachometer. When the maximum number of revolutions of the internal combustion engine is reached, we unscrew the screw to the left by 180 degrees, the adjustment is over.

Sometimes only correct setting and the use of the device reveals its full potential. You do not need to neglect it and carry it out as needed.

Video: how is the carburetor adjustment of the petrol cutter