Kaasuttimet

Kaasuttimet, often translated as carburetors in English, are mechanical devices used in internal combustion engines to mix air and fuel in the correct ratio for combustion. They were the primary fuel delivery system for gasoline engines for many decades before being largely superseded by fuel injection systems.

The basic principle of a carburetor involves the Venturi effect. As air is drawn through a constricted passage within the carburetor, its velocity increases, and its pressure decreases. This lower pressure creates a vacuum that draws fuel from a reservoir, called a float bowl, through small jets and into the airstream. The fuel then atomizes, breaking into fine droplets, as it mixes with the incoming air.

The amount of air-fuel mixture entering the engine is controlled by a throttle valve, typically operated by the accelerator pedal or lever. Different circuits within the carburetor are designed to provide the appropriate mixture for various engine operating conditions, such as idling, acceleration, and full power. These circuits include idle jets, main jets, and accelerator pumps.

While effective, carburetors have limitations. They can be sensitive to temperature and altitude changes, leading to suboptimal performance. They are also less precise in fuel delivery compared to modern fuel injection systems, which can result in lower fuel efficiency and higher emissions. Despite these drawbacks, carburetors are still found in some older vehicles, motorcycles, small engines like those in lawnmowers and chainsaws, and in certain racing applications where simplicity and tunability are prioritized.