This workshop service manual covers the Mercury Mariner 9.9 HP outboard motor, a robust 2-stroke, water-cooled engine designed for reliable performance. Featuring a 262 cc displacement, CD ignition system, and direct drive transmission with Forward-Neutral-Reverse gear selection, this motor is engineered for demanding marine applications. Available with standard and long shaft options, it offers versatility for various boat types. The Mariner 9.9 HP is built with the quality and durability expected from Mercury, ensuring consistent power and efficiency for recreational and professional use. This comprehensive manual provides detailed information essential for the maintenance, repair, and overhaul of your Mercury Mariner 9.9 HP outboard motor. It includes critical technical specifications, lubrication requirements, and general maintenance procedures such as spark plug gap settings and recommended fuel octane. Designed for technicians fully conversant with general marine practices, this English-language guide ensures that owners and service professionals have the necessary knowledge to keep the motor operating at peak performance and reliability.