This Service and Repair Manual covers the Mercury MerCruiser R, MR Alpha, Alpha One, and Alpha One SS sterndrives, generation 1. These sterndrives are known for their robust engineering and reliability, making them a popular choice for various marine applications. This manual is designed to provide comprehensive information for owners and technicians alike, ensuring the continued performance and longevity of these marine propulsion systems. The purpose of this manual is to offer detailed guidance on the maintenance, repair, and troubleshooting of the specified Mercury MerCruiser sterndrive models. It includes step-by-step instructions, detailed illustrations, and technical specifications covering areas such as transom assemblies, sterndrive units, gear ratios, power trim systems, steering systems, and corrosion protection. This resource is intended for both do-it-yourselfers and experienced mechanics, empowering them with the knowledge to perform necessary service and repairs effectively.