This model shows the internal structure and operating principles of a water cooled four-stroke engine. The valves are clearly evident, cams being driven by a gear train from the rear of the main crank. This is the chain driven overhead camshaft type and all functional components (camshaft, rock-arms, tappets, etc.) are clearly demonstrated. The functioning of the fuel injection system is also represented. Cross sections of the carburettor and fuel supply are shown. Hand powered motion supplied through a crank demonstrates the moving parts of the engine. Crank shaft, piston, valves and cams cycle through all stages of the four-stroke process as the hand crank is rotated. Ignition light can be simulated by using a 2 AA Batteries (not included). Solidly constructed out of aluminium and plastic. Model is mounted on metal stable base with printed diagram and key components.