Ninja 400 numbers isn’t Kawi-supplied media-kit. Came from instrumented testing along with real-world dyno.
https://www.cycleworld.com/2019-yama...aki-ninja-400/ 
To really understand how much faster 400 is than 250, just compare their laptimes at Thunderhill track:
https://racehero.io/events/afm-thund...ts-afm/results
Legacy 250:
2:17, 2:18
400 Superbike:
1:55
400 Superstock: 1:57
Ninja Cup (300 & 400): 400=1:56
300WSS: R3=2:07
450SS (cripple 600s): R6=1:58
LightweightTwins: N400=1:55
MiddleweightTwins: SV650=1:57
LegacyHeavyweight: GSX-R750=1:56
750 Superstock: #3 R6=1:55
600 Superstock: #4 R6=1:56
600 Superbike: #4 R6=1:55
OpenGP: #6 R1=1:55
FormulaPacific: #8 S1000RR=1:54
Two remaining 250 racers
are 120-125lb jockeys and they don’t stand a chance against Ninja 400. Which leaves them in dust of over 1/3-mile PER LAP (22-sec faster). It catches and laps them every 6 LAPS!
Ninja 400 is so light and fast, it would win outright in many of larger classes (comparable to R6). It’s faster than SV650 and GSX-R750. Can get top-10 against biggest bike classes!
