Which sequence represents the steps of a four-stroke outboard engine?

The correct sequence for a four-stroke outboard engine is indeed intake, compression, power, and exhaust. This process is fundamental to how the engine operates to convert fuel into mechanical energy.

During the intake phase, the engine's piston moves down, creating a vacuum that draws in a mixture of fuel and air through the opened intake valve. Following that is the compression phase, where the piston rises and compresses the fuel-air mixture, making it more volatile and ready for combustion.

Next comes the power phase, also known as the combustion phase, where the spark plug ignites the compressed fuel-air mixture. This explosion forces the piston down, generating power that turns the crankshaft and ultimately drives the propeller.

Finally, during the exhaust phase, the piston moves back up, pushing out the spent gases through the opened exhaust valve. Once this cycle completes, the next cycle begins with the intake stroke.

Understanding this sequence is crucial for anyone operating or maintaining a four-stroke engine, as each step is integral to the engine's efficiency and power generation. Recognizing the correct order reinforces the concepts of engine function and mechanical processes.