Why governor is not using in the petrol engine?

A governor is a device that controls the speed of an engine by regulating the flow of fuel or air to the engine's combustion chamber. In petrol engines, the flow of fuel is typically controlled by a carburetor or fuel injector, while the flow of air is controlled by a throttle valve.

Governors are not used in petrol engines because they are not necessary. In a petrol engine, the speed of the engine is primarily determined by the amount of fuel that is injected into the combustion chamber. The flow of fuel is controlled by the carburetor or fuel injector, which is actuated by the accelerator pedal. As the accelerator pedal is pressed, the carburetor or fuel injector opens wider, allowing more fuel to flow into the combustion chamber. This causes the engine to speed up.

In contrast, a diesel engine requires a governor to control the engine speed. In a diesel engine, the fuel is injected directly into the combustion chamber. The amount of fuel that is injected is determined by the governor. The governor senses the engine speed and adjusts the amount of fuel that is injected accordingly. This ensures that the engine speed does not exceed a safe level.

In summary, governors are not used in petrol engines because they are not necessary. The speed of a petrol engine is controlled by the amount of fuel that is injected into the combustion chamber, which is regulated by the carburetor or fuel injector.