This manual covers Mercury Mariner 4hp, 5hp, and 6hp 4-stroke outboard engines, identified by serial numbers starting with OR000001. These engines are engineered for reliable performance in various marine applications. Their robust construction and efficient 4-stroke design ensure dependable operation, making them a suitable choice for recreational boating and other watercraft needs. The Mercury Mariner 4hp 5hp 6hp 4-Stroke Outboard Repair Manual provides comprehensive guidance for maintenance, repair, and troubleshooting. It includes detailed, step-by-step procedures, clear illustrations, and diagrams for all major components, including the fuel system, ignition and electrical systems, power head, and gearcase. This manual is designed to assist owners, technicians, and mechanics in keeping these outboards in optimal working condition.