This manual covers the Yamaha 2 SD Outboard, a 1990 model year outboard motor designed for marine propulsion. Engineered with a reliable 2-stroke, 2-cylinder gasoline engine, this unit exemplifies Yamaha's commitment to quality and performance in the marine industry. Its robust construction and efficient design make it a dependable choice for various boating applications, ensuring consistent power and operation on the water. The purpose of this Factory Service Manual is to provide comprehensive guidance for the maintenance, repair, and servicing of your Yamaha 2 SD Outboard. It details step-by-step maintenance procedures, including disassembly, inspection, repair, and assembly, supported by exploded diagrams to aid understanding. This resource is essential for owners, mechanics, and technicians to effectively maintain the vehicle's optimal performance and longevity.