Observation

This question was extremely difficult for the candidates as they could not provide the required responses to the various parts of the question.  The required responses to the various parts of the question are:

4.         (a)        It is a two-stroke, spark-ignition engine or two-stroke petrol engine.
It is also called a two-stroke valveless engine or two-stroke three-port engine.

            (b)        V – deflector;
W – transfer port;
Y – exhaust port;
Z – crankcase.

(c)        The purpose of V is to direct the charge up thus preventing its escape.  W is to allow the partially compressed charge pass to the upper part of the piston while Z allows for partial compression of the fresh charge or it accommodates the engine rotating parts.

(d)        It employs a system of lubrication called petroil where the recommended quantity of oil is mixed with petrol to lubricate the internal parts of the engine.