How long do you operate a blower before starting an engine on a boat?

Before starting an engine on a boat, it's recommended to operate the blower for at least 4-5 minutes. This helps to ventilate the engine compartment and remove any potentially harmful fuel vapors. Always check that the blower is functioning correctly and ensure that the engine compartment is well-ventilated before starting the engine. Following this procedure enhances safety and reduces the risk of fire or explosion.