This workshop service repair manual covers the Mercury Mariner Outboard, a powerful 100 HP outboard motor. Designed for reliable marine propulsion, this engine features an inline 4-cylinder configuration and a water-cooled system. Its robust engineering and quality construction are hallmarks of Mercury marine products, ensuring dependable performance for a wide range of boating applications. This manual provides comprehensive information to understand and maintain the operational integrity of your Mariner Outboard. The purpose of this manual is to serve as an authoritative guide for the maintenance, repair, and servicing of the Mercury Mariner Outboard. It details essential procedures, technical specifications, and troubleshooting steps necessary for optimal engine performance and longevity. Owners, technicians, and mechanics will find detailed instructions on lubrication, scheduled maintenance intervals for components like spark plugs and fuel filters, and other critical operational data. This resource is designed to empower users with the knowledge required to keep their Mercury Mariner Outboard in peak condition.