Technician A and Technician B statements about engine strokes: Who is correct?

• A. Technician A
• B. Technician B
• C. Both Technicians
• D. Neither Technicians

Answer: (A)

Engine strokes in a four-stroke cycle follow a specific order: intake, compression, power, exhaust. The intake stroke moves air-fuel into the cylinder as the piston travels downward with the intake valve open. The compression stroke then seals the chamber and compresses the mixture as the piston moves upward. The power stroke occurs after ignition when the combusted gas expands, pushing the piston downward. Finally, during the exhaust stroke, the exhaust valve opens and the piston moves upward to expel the burnt gases.

Technician A is correct because their statement lines up with this standard sequence and valve behavior. If Technician B described anything that contradicts this order or the valve actions, that would make their statement incorrect.