1) Carburettor & Choke
It is a device used to blend the air and fuel in a certain ratio which is required for the combustion in engine. The amount of mixture to be allowed to the engine is controlled by the throttle.
2) Crank
It is attached to the arm which connects the piston so that the reciprocating motion is received and converted to the circular motion.The second image shows the engine motion without crank to show the importance of crank.
