The Kawasaki Ninja's peak power has dropped despite its bigger engine, but does that really matter?

Updated: 14 August 2025

“It’s got more capacity, but it makes less peak power. What’s that all about, eh?” If I had a quid for every time someone’s asked me that question this year, I’d have myself enough for at least a tankful of Super Unleaded, with perhaps even a Twix thrown in, too.

Update one: First impressions after a 14-year reunion
Update two: Why this Kawasaki is so tempting to ride at any opportunity
Update three: Testing the Kawasaki’s comfort on a weekend jaunt

Kawasaki’s Ninja SX has bulged in capacity by 56cc – more than a twist-and-go’s worth of volume – and yet its claimed peak power has reduced by 6bhp; down from 140bhp @ 10,000rpm to 134bhp @ 9000rpm.

The reason Kawasaki have done this is two-fold; firstly, the increase in capacity is a direct result of making Britain’s best-loved sports-tourer Euro5+ compliant. The tuning required to meet emissions targets (such as leaner mixtures and retarded ignition timing) has the effect of reducing torque, peak horsepower and throttle response, so increasing capacity compensates for these losses.

Secondly, a longer stroke motor (the 1100SX’s capacity increase has been achieved via a 3mm stretch to its stroke) naturally boosts torque at lower revs and makes for a smoother delivery, basically because the larger-lunged motor is doing the same work for less effort.

Kawasaki know their customers and understand that the many buyers of this massively popular performance-bike-with-panniers value smooth shove rather than frantic ferocity so they’ve given the new bike milder cams combined with a reworked head to sacrifice some of that top end for a more usable swell of midrange.

But what does that actually mean in terms of hard facts? Firstly, to see how the 1100SX’s engine performance compares with the 2024 Ninja 1000SX, I took my bike down MCN’s regular dyno at BSD Performance to find out.

In terms of peak power, the new 1100SX produces 124.7bhp @ 9200rpm and a maximum torque of 77.8lb.ft @ 7600rpm. Whereas the outgoing model, the 1000SX, makes 130.4bhp @ 9800rpm and peak torque of 78.2lb.ft @ 7600rpm – that’s 6bhp down, as claimed.

Who rides around at peak rpm, though? The low and midrange is where engine performance is most important for road riders, especially for sports-touring, and it’s here where the Ninja 1100SX outperforms the 1043cc SX. At 4000-7000rpm the 1100 is at worst 6bhp stronger than the old bike and at best 8bhp more powerful. It makes more power and torque everywhere, with the 1000SX only usurping it past 7000rpm.

What does that extra grunt translate to in terms of raw performance when you are out on the road? Well, I’ll soon be getting my hands on a Ninja 1000SX and riding it back-to-back with my bike to find out just whether the new Kawasaki’s motor and gearing revisions really do make it a more versatile and smoother ride, or whether that extra buzz of top end performance is missed.

How fast does it go?

Yeah, top speed is irrelevant, but just in case you’re a Ninja 1100SX owner who happens to find themselves on an unrestricted stretch of German autobahn this summer, the new bike tops out at an indicated 166mph which translates to an actual 157.75mph (minus its panniers, of course!).