This manual covers the Mercury Mariner 30 HP EFI 4-stroke outboard engine, produced between 2002 and 2005. This engine is designed for reliable performance, featuring a 4-stroke configuration and Electronic Fuel Injection (EFI) for efficient operation. Its robust engineering ensures dependable power for various marine applications, making it a trusted choice for boaters. The purpose of this Service Repair Manual is to provide comprehensive guidance for the maintenance and repair of your Mercury Mariner outboard. It details essential procedures, technical specifications, and troubleshooting steps necessary to keep your engine in optimal condition. This manual is an indispensable resource for owners, technicians, and mechanics seeking to understand and maintain the functionality and longevity of their 2002-2005 Mercury Mariner 30 HP EFI 4-stroke engine.