The Kawasaki Ninja 400 remains a strong used sport-bike option for riders who want a smooth parallel-twin engine, manageable dimensions and fully faired styling. Since it is discontinued in India, the key question is whether a particular motorcycle has clean paperwork, credible service history, healthy consumables and a price that still makes sense against newer alternatives such as the Ninja 500 and Aprilia RS 457. With a 399cc liquid-cooled twin-cylinder engine, 45 PS, 37 Nm, a six-speed gearbox, dual-channel ABS, a 785mm seat height and a 168kg kerb weight, it suits riders seeking an engaging weekend machine, a first premium twin-cylinder sport bike or a capable platform for track-day skill…