Sadly, power in the Ninja ZX-4RR is expected to be down by as much as 25% from the European spec that produces up to 79 hp. The drop in power is thanks to a rev limiter that will cap RPMs due to noise regulations.
How Much Power Does The 2023 Kawasaki Ninja ZX-4RR Make?
If the idea of a high-revving 399cc four-cylinder piques your interest, you may be disappointed by the power output of the US-spec Kawasaki Ninja ZX-4RR.
"Sure, the Vulcan’s got 250cc over the ZX-4RR, but customers expect more from a four-cylinder Ninja, especially one with a double-R designation. So, what gives?
The most likely culprit is a lower rev limit. Kawasaki Canada notes on its official website that the ZX-4R and ZX-4RR “have a maximum RPM of 11,500 rpm in Canada due to noise regulations.” Those regulations state a maximum volume between 78 dBA and 83 dBA, depending on the testing methodology.
Regulations in America vary by the state, but many fall somewhere within that range for motorcycles travelling at speeds faster than 35 mph. This leads us to believe that the U.S.-spec Ninja ZX-4RR also has a maximum engine speed limited well below the 16,000 rpm indicated on the issued press photos (which note they are for European spec models), but also below the “over-15,000 rpm redline” Kawasaki USA claims in its materials.
We reached out to Kawasaki USA about the Ninja’s rev limit and were told they were awaiting final confirmation on specs from Japan. So, like their European counterparts say, specifications may still be subject to change. We’ll provide an update when Kawasaki USA has more to tell us.
An actual limit within the 11,000 to 12,000 rpm range is about 75% of the “over-15,000 rpm” claimed redline, which may be enough to choke the U.S.-spec Ninja ZX-4RR down to a 56.3 hp output from the European figures."
