The base horsepower for a KTM 990 Adventure motorcycle is approximately 105 horsepower. The KTM 990 Adventure is powered by a 999cc, liquid-cooled, V-twin engine that delivers strong performance and torque suitable for both on-road and off-road adventures. It's worth noting that specific horsepower figures may vary slightly depending on factors such as model year and any modifications or aftermarket additions made to the motorcycle.