How Much Power Does the 2025 Kawasaki KX450 Make?

Dyno testing Kawi’s MY25 flagship motocross bike for horsepower and torque.

Kawasaki’s KX450 wasn’t the strongest performer on the dyno in its previous-generation (20192023) platform, but that changed with the introduction of the 2024 model. Revisions to its fuel-injected liquid-cooled DOHC four-stroke 449cc single-cylinder engine such as a 5mm-longer connecting rod, 2mm-smaller intake valves, and different layout for the entire intake system all contributed to the 2024 model churning out 1.6 hp more than the 2023 model at peak.

Being that Team Green’s flagship motocross bike is mechanically unchanged for 2025, it makes similar figures as the prior year with 53.5 hp and 33.0 lb.-ft. of torque at the rear wheel, as measured by Dirt Rider’s in-house Dynojet 250i dynamometer.

“The Kawasaki is sneaky fast and smooth,” test rider Casey Casper said. “Having the least exciting 450 power in stock trim, it’s better suited for vet riders and those who appreciate smooth power curves.”

2025 Kawasaki KX450 Dyno Chart.Robert Martin

2025 Kawasaki KX450 Engine Specs

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