Question

Which part of the idling circuit of a carter carburetor the engine suction is applied through which air and fuel are drawn?

(a) Low-speed port

(b) Main nozzle

(c) Idle port

(d) Metering rod

This question was addressed to me in an online interview.

My doubt stems from Petrol Engine Fuel Supply System in chapter Petrol Engine Fuel Supply System of Automotive Engine Design

Answer 1

The correct choice is (c) Idle port

Explanation: For idling circuit, the throttle valve is almost closed and the whole engine suction is applied at the idle port, through which the air and the fuel are drawn giving rich mixture. This rich mixture requires more fuel for the proper combustion.