This document covers the Mercury Mariner 20 HP JET outboard engine. Designed for reliable performance, this gasoline-powered engine features a jet drive transmission, offering a unique propulsion solution. Its robust construction and engineering are intended to provide dependable operation for various marine applications. This Factory Service Repair Manual provides comprehensive guidance for maintaining and repairing the Mercury Mariner 20 HP JET. It includes detailed procedures for routine maintenance, troubleshooting common issues, and understanding technical specifications. The manual is designed to assist owners and technicians in ensuring the optimal performance and longevity of the engine.