Thunder Tiger Four Stroke series are manufactured by automated computer-controlled machinery, resulting in a product that looks and performs better. Special Camshaft and oversize valves combine to improve performance and ease handling. Precision air bleed carburetor makes adjustments simple, and efficient mufflers keep things quiet at the field. Perfect for the pilot looking for the authentic aircraft sound. Thunder Tiger's powerhouse F-54s is the perfect way to enjoy the advantages of four-stroke performance; the ability to swing a larger prop, increase torque, lower noise and improved fuel economy.