How does carburetor icing typically occur?

Carburetor icing typically occurs when the lowered pressure causes a decrease in the temperature of the fuel/air mixture as it passes through the carburetor. In carbureted engines, air and fuel are mixed in the carburetor before entering the engine. As the mixture moves through the venturi (a narrowing in the carburetor), the decrease in pressure leads to a drop in temperature due to the principles of thermodynamics. This drop in temperature can lead to the formation of ice in the carburetor, particularly when the humidity is high.

Humidity can contribute to the icing process because it provides moisture that can freeze. However, the direct cause of the icing is primarily related to the thermodynamic effect of the pressures and temperatures involved during the mixing of air and fuel.

While engine overheating and incorrect fuel mixture might cause performance issues, they are not directly related to the phenomenon of carburetor icing. Understanding the relationship between pressure and temperature in this context is crucial for recognizing how carburetor icing develops.