This Service & Repair Manual covers the Mercury 30 EFI / 40 EFI FourStroke outboard engine, model year 2002, with serial numbers starting from 0T409000. Engineered for reliability and performance, these FourStroke Electronic Fuel Injection (EFI) engines deliver 30 to 40 horsepower, making them suitable for a variety of marine applications. The manual provides comprehensive details on the engine's robust design, including its powerhead, mid-section, and lower unit, all contributing to its reputation for quality and durability on the water. This manual serves as an essential resource for maintaining and repairing your Mercury outboard. It details crucial procedures for scheduled maintenance, lubrication, electrical system diagnostics, and troubleshooting the Electronic Fuel Injection (EFI) system. With clear instructions and high-quality diagrams, this English-language guide empowers owners, mechanics, and technicians to ensure optimal performance and longevity of their engine, covering all aspects from basic operation to complex component repair.