This manual covers the Mercury Mariner 30/40 HP 2 Cylinder Outboard, a robust marine engine designed for reliable performance. Engineered for durability and efficiency, this outboard motor delivers consistent power across its operational range, making it suitable for a variety of watercraft and boating applications. Its 2-cylinder configuration and water-cooled system are central to its efficient operation and longevity, ensuring a dependable experience on the water. This comprehensive Factory Service Repair Manual provides essential information for maintaining and repairing your Mercury Mariner outboard. It details critical procedures, technical specifications, and troubleshooting guidance necessary for optimal performance and longevity. Owners, technicians, and mechanics will find the English-language documentation, spanning hundreds of pages, invaluable for all service and repair needs, ensuring the continued reliability of the 30/40 HP 2 Cylinder Outboard.