Mercury Owners Manual (Portuguese) - 90-818936H50. The Mercury Owners MNL-Portug - 90-818936H50 is the official Portuguese-language owner's manual designed by Mercury Marine to provide clear, model-specific guidance for safely operating and maintaining your Mercury outboard engine. Ideal for Portuguese-speaking boaters, this manual includes comprehensive instructions straight from the manufacturer.. Key Features. Factory-Authorized Manual - Developed and published by Mercury Marine. Portuguese L