The Mercury Mariner 150 HP DFI Optimax, produced between 2000 and 2005, represents a robust V6 outboard engine featuring a 2.4-liter displacement and Direct Fuel Injection (DFI) technology. This model delivers 150 horsepower, engineered for reliability and performance in demanding marine environments. Its advanced DFI system ensures efficient fuel delivery and optimal combustion, contributing to its reputation for power and durability. The DFI Optimax series is designed for boaters who require dependable power and advanced technology for a wide range of applications. This comprehensive Workshop Service Manual provides detailed information for the repair and overhaul of the Mercury Mariner 150 HP DFI Optimax models from 2000-2005. It covers essential maintenance procedures, troubleshooting guidance, technical specifications, and safety protocols necessary for proper upkeep. The manual is an indispensable resource for owners, mechanics, and technicians, offering the expertise required to maintain the engine's peak performance and longevity. All instructions and data are presented in English to ensure clarity and ease of use.