Yanmar 2GM: Reliable Inboard Diesel Propulsion for Small Vessels The Yanmar 2GM is a compact, twin-cylinder inboard diesel engine engineered for marine propulsion, delivering dependable power to small boats and auxiliary systems. Produced from 1980 to 1984, this 4-stroke, single-acting engine embodies Yanmar’s legacy of robust marine engineering, providing 15 horsepower (11 kW) at 3,600 RPM under DIN 6270B rating for efficient, low-end torque in demanding saltwater environments. Key technical specifications underscore its marine-ready design: a 586 cm³ (35.8 in³) displacement with a square bore and stroke of 72 mm each, ensuring balanced power delivery. Weighing just 100 kg (220 lbs), it features seawater cooling for superior corrosion resistance and heat dissipation, making it ideal for prolonged operation in harsh marine conditions. As a diesel-fueled inboard unit, it operates on a 4-stroke cycle, minimizing emissions and maximizing fuel economy compared to gasoline alternatives. Marine-specific benefits include its vibration-dampening single-acting cylinders, which promote smooth, quiet performance essential for crew comfort on pitching decks. The seawater-cooled system excels in preventing thermal overload during extended voyages, while the compact footprint optimizes engine bay space in space-constrained hulls. Yanmar’s durable construction—resistant to saltwater ingress and mechanical stress—reduces maintenance intervals, lowering operational costs and downtime for vessel owners. Performance-wise, the 2GM shines in low-speed applications, offering strong low-RPM torque for precise maneuvering and trolling, with inherent diesel efficiency supporting long-range cruising without excessive fuel burn. Though limited to 3,600 RPM max, it prioritizes reliability over high-speed bursts, avoiding the wear common in over-revved setups. Ideal for small fishing boats, personal yachts, or auxiliary power in cruisers under 30 feet, the Yanmar 2GM remains a timeless choice for recreational and light commercial mariners seeking unyielding dependability in compact marine propulsion. Its legacy support from Yanmar ensures viability even for vintage installations, blending efficiency with enduring seaworthiness.