Question

What is the number of rotation that has to be given to the idle screw to adjust the carburetor?

(a) 2

(b) 2.5

(c) 1

(d) 3

I had been asked this question at a job interview.

I'd like to ask this question from Petrol Engine Fuel Supply System topic in section Petrol Engine Fuel Supply System of Automotive Engine Design

Answer 1

The correct option is (b) 2.5

To elaborate: The carburetor is screwed in completely and then opening back by two and a half turns. This screwing in the same decreases the idle port area and hence decreases the engine speed. The screw is adjusted until the engine runs smoothly at the required speed.