Basic Powerboating, Safety and Rescue Practice Test

In the operation of a two-stroke outboard motor, the engine completes a power stroke and a compression stroke within just two movements of the piston, allowing the engine to power the boat effectively and efficiently.

During a power stroke, fuel and air are ignited, which drives the piston down and generates power. This is critical to the motor's function, as it propels the boat forward. Following this, the compression stroke takes place, where the fuel-air mix is compressed within the cylinder to prepare for ignition in the next cycle. This efficient combination of strokes allows the two-stroke engine to deliver power with fewer moving parts compared to a four-stroke engine.

Other choices involve strokes that are not accurately aligned with how a two-stroke engine operates. For example, the intake stroke is not a separate action in a two-stroke engine; rather, the intake of fresh fuel and exhaust is managed in one continuous motion with the power and compression strokes occurring more rapidly. Similarly, the exhaust stroke is typically not regarded as a distinct stroke in the context of two-stroke operation, as it occurs simultaneously with the intake. Therefore, recognizing the significance of the compression and power strokes is essential for understanding the mechanics of a two-stroke outboard motor