What is the purpose of the venturi on a carburetor?

The venturi on a carburetor is designed to increase air speed and decrease pressure. This function is crucial for the carburetor’s operation, as it creates a differential pressure that draws fuel into the air stream. As air passes through the narrowing section of the venturi, it accelerates, leading to a drop in pressure according to Bernoulli's principle. This lower pressure allows fuel to atomize and mix with the incoming air, forming a combustible mixture that is essential for engine performance.

Understanding this principle helps clarify why fuel delivery and combustion efficiency are directly impacted by the design of the venturi. It reflects the critical role of air dynamics in engine operation, highlighting how the venturi maintains an optimal mixture ratio for various engine speeds and loads.