Answer for What are the main parts in the fuel system of petrol engine?

(i) One part delivers the mixture of petrol and air to the cylinder in a right proportion (or ratio). This is called carburettor. (It is a device which converts liquid fuel into vapour and mixes it with air in such proportion as to form the most efficient combustible mixture).
(ii) The other part which delivers petrol to the carburettor from the petrol tank.