How Much Power Does the 2023 Kawasaki KX450 Make?

Dyno testing Kawasaki’s 450cc motocross bike for horsepower and torque.

Since its last major overhaul in 2019, Kawasaki’s KX450 hasn’t produced the most horsepower or torque in the class. This year is no different, as the green machine’s fuel-injected liquid-cooled DOHC four-stroke 449cc engine churned out 51.9 hp and 32.6 lb.-ft. of torque on Dirt Rider’s in-house Dynojet 250i rear-wheel dynamometer. With those figures, it ranks sixth in peak hp and seventh in maximum torque (when including Suzuki’s RM-Z450, which didn’t participate in our 2023 450 Motocross Shootout).

Despite its less-than-stellar performance on the dyno, the KX450 mill shines in the dirt. That’s just one of the many reasons why it won our 450 motocross bike comparison test in 2019, 2020, 2021, and 2022, and finished in the runner-up spot this year. Team Green is a prime example that power isn’t everything in this segment.

2023 Kawasaki KX450 Dyno Chart.Robert Martin Jr.

2023 Kawasaki KX450 Engine Specifications

Engine Type: DOHC, liquid-cooled, four-stroke single-cylinder; 4 valves/cyl.
Displacement: 449cc
Bore x Stroke: 96.0 x 62.1mm
Compression Ratio: 12.5:1
Fuel Delivery: Electronic fuel injection w/ 44mm throttle body