This service repair manual covers the 1981 Mercury Mariner 18HP Outboard Motor. Engineered for reliability and performance, this outboard motor is designed for a wide range of marine applications. Its robust construction and efficient 18-horsepower engine ensure dependable operation for both recreational and professional use. This manual provides comprehensive information to keep your Mercury Mariner operating at its peak. This manual serves as an essential resource for maintaining and repairing your 1981 Mercury Mariner 18HP Outboard Motor. It details a wide array of procedures, from routine maintenance tasks such as oil changes to more complex repairs like transmission swaps. With step-by-step guidance, numerous illustrations, and easy-to-read text, this searchable and printable document empowers owners and technicians alike to perform necessary work with confidence, ensuring the longevity and optimal performance of the outboard motor.