What should be checked to ensure effective cooling when starting the motor?

To ensure effective cooling when starting the motor, checking that the water impeller is not clogged is essential. The water impeller is a critical component of the cooling system in a boat motor; it pumps water from outside the boat through the engine to keep it cool during operation. If the impeller is clogged, it restricts the flow of water, which can lead to overheating of the motor and potential damage. Proper cooling is vital for the safe and efficient operation of the engine, as overheating can cause severe mechanical failures.

While factors like a clear fuel line, a charged battery, and a functional electrical system are important for the overall operation of the boat and its motor, they do not specifically relate to the cooling effectiveness of the engine at startup. Therefore, ensuring that the water impeller is free of obstructions is the most crucial step in preventing overheating and ensuring that the engine runs smoothly from the very beginning.