The operating principle of float-type carburetors is based on the Bernoulli’s theorem which states that the energy per unit mass of a moving fluid is constant. As the air passes through the convergence of the Venturi duct, its velocity increases causing a drop in pressure and temperature. The pressure will drop proportionally to the mass airflow and is used to make fuel flow from the float chamber by placing a ‘U’-shaped jet into the Venturi. Engine suction creates a difference in air pressure at the throat of the Venturi duct and the air inlet resulting in a sucking effect. Besides the drop in pressure and temperature at the Venturi’s throat, the later will increase again within the induction manifold as the throttle is opened.

• “freezing temperature of the air entering the carburettor” – carburettor icing doesn’t necessarily occur only when freezing temperatures are prevailing. As long as you have visible moisture and the temperature is below +10°C (but also higher under certain conditions), the risk of icing becomes significant.
• “Low volatility of aviation fuel” – this property is not linked at all to carburetor icing.
• “Compression of air at the carburettor venturi” – compression will have the opposite reaction, the temperature and pressure will increase. Whereas the venturi decreases the temperature and the pressure of the flowing fuel and air.