Red Seal Agricultural Equipment Technician Practice Exam

What is the primary function of a carburetor?

1. To clean the engine components

2. To mix air and fuel in the correct ratio for combustion

3. To control the engine temperature

4. To ignite the fuel

The correct answer is: To mix air and fuel in the correct ratio for combustion

The primary function of a carburetor is to mix air and fuel in the correct ratio for combustion. This device plays a crucial role in internal combustion engines by ensuring that the right amount of fuel is combined with the incoming air. The mixture must be precise because an overly rich mixture (too much fuel) can lead to inefficient combustion and fouling of spark plugs, while a lean mixture (too much air) can cause the engine to run hot and potentially damage engine components. The carburetor does this by utilizing different mechanisms, such as venturi effects and jets, to regulate the fuel flow based on the engine's power demands and speed. Ensuring the optimal air-fuel mixture allows for smooth engine operation, better fuel efficiency, and reduced emissions. This function is vital for the proper performance of gasoline engines as they rely on this mixture to operate effectively. Other options presented relate to alternative functions, such as engine cleaning, temperature control, or ignition, which are not the primary responsibility of the carburetor.