Passage 1: The Outboard Motor
An outboard motor is the engine often seen on the back of a boat. It helps push the boat through the water. The motor sits outside the boat, which is why it is called an outboard motor.
Inside the motor are many important parts. Fuel moves into the engine. A spark plug makes a tiny spark. That spark helps burn the fuel. The burning fuel creates power.
That power spins a shaft. The shaft turns the propeller. The propeller pushes water backward. This makes the boat move forward.
Outboard motors also need cooling. Water moves through small tubes inside the motor to keep it from getting too hot.
Passage 2: Inside the Inboard Engine
An inboard engine is different because it sits inside the boat. Many larger boats use inboard engines. The engine connects to a long shaft underneath the boat.
Like an outboard motor, an inboard engine uses fuel, air, and a spark to make power. Pistons move up and down very fast. This movement turns the shaft and spins the propeller.
Inboard engines are often quieter because they are inside the boat. They are also protected from waves and splashing water.
Both engines help boats move, but they are built in different places. One is outside the boat, and one is inside.