What is the reason why a motorcycle will stall as soon as it increases its throttle?

In the initial idle period of carburetor, only the idle metering hole in carburetor can deliver combustible mixture to cylinder head, mainly to stabilize idle speed, because the main metering hole is blocked by oil needle.

At the beginning of riding, the intake air volume increases instantly when the throttle is increased, which makes the mixture in the cylinder head too thin, which makes the combustible mixture of the engine unable to burn continuously in a short time, resulting in the symptom that the speed cannot be increased.

When the oil needle moves up and the main metering hole starts to work, the mixed gas can gradually return to the normal state, and there will be no more symptoms of not increasing the speed.

Causes of unstable idle speed

(1) Inappropriate ignition time, resulting in poor idle speed;

(2) the engine leaks air;

(3) The spark plug electrode gap is incorrect;

(4) The idle hole of carburetor is not smooth;

(5) Incorrect gasoline label (low octane number);

(6) The air filter muffler is blocked;

(7) The gasoline quality is not up to standard.

Extended data:

Throttle, also known as "throttle" and "throttle". Refers to the control device that controls the engine power (thrust). On the piston aero-engine, the throttle valve controls the opening of the carburetor to control the filling amount of the cylinder, thus determining the output power of the engine.

On the gas turbine engine, the throttle valve controls the metered fuel flow of the fuel regulator, thus determining the thrust generated by the engine. The position of the throttle is controlled by the driver operating the throttle lever in the cockpit, and it is transmitted to the carburetor or fuel regulator on the engine through control system components such as pull rod, rocker arm, torsion tube, steel cable, pulley and sector wheel. On an airplane, the throttle lever is always pushed forward to increase power (thrust) and pulled back to decrease power (thrust).

Causes of abnormal sound of throttle valve

1) Throttle is stuck due to carbon deposition, so clean the throttle;

2) The accelerator pedal support pin is worn. Adding butter can solve the problem. If it fails, replace it.

3) The throttle line is not installed correctly. If it is an electronic accelerator, please check the accelerator pedal mechanism and the accelerator pedal sensor.

Baidu encyclopedia: throttle