The most important thing in any vehicle or motorcycle is the engine, and Kawasaki did a great job in this part of their Ninja 400. The all-new engine is a liquid-cooled, DOHC, fuel-injected, 399 cc parallel-twin with four valves per cylinder. The new Ninja 400 has 44.8 horsepower and 28 pound-feet of torque. However, the most significant thing that Kawasaki did to Ninjas powertrain is... the style of the new bike. Despite having a bigger engine, Kawasaki says the Ninja 400 is about 17.6 pounds lighter than the Ninja 300. This is thanks to a lightweight trellis frame, which you can see below.