This manual covers the Yamaha EK25BMH, a 2-stroke, air-cooled engine with a displacement of 25 cc. It features a diaphragm type, floatless carburetor and a CDI ignition system. The engine requires a fuel mixture of 50:1 gasoline to Yamaha 2-stroke oil and has a fuel tank capacity of 0.5 L. Its dry weight is 2.2 kg for the engine only. This engine is designed for reliable performance in its intended applications. The Yamaha EK25BMH Service Repair Manual provides comprehensive information for maintenance and repair. It details engine specifications, including bore x stroke dimensions and recommended spark plugs. The manual outlines transmission details, such as the centrifugal clutch and direct drive system. It also covers essential maintenance procedures, recommended fuel types, and oil specifications, ensuring proper upkeep and longevity of the EK25BMH unit.