Power to victory
The Unicam engine that powers both the CRF450RX and CRF450R has been radically improved for 2017, with more horsepower, more torque, and a higher rev limit. The RX’s engine has special ignition mapping to suit the unique demands of cross-country and endurocross competition.
New cylinder head
Completely new Unicam cylinder head design uses finger rocker arms, oval cross-section valve springs, bigger intake valves, and increased valve lift to boost horsepower and allow a higher rev limit.
Improved combustion efficiency
By straightening the intake path, reducing valve angle, and revising both combustion chamber and piston shape, engineers were able to improve flow and increase compression ratio for an even bigger power boost.
A new scavenge pump system with no separate oil tank improves engine lubrication, reduces friction, and requires less oil for reduced overall engine weight.
Programmed for power
The CRF450RX’s Programmed Fuel Injection (PGM-FI) settings contribute to the engine’s strong low-end torque, remarkable top-end power and generous over-rev capability.
Engine Mode Select button
The CRF450RX’s Engine Mode Select (EMS) system lets you modify fuel-injection and ignition mapping with the simple push of a handlebar-mounted button. Choose between Standard, Smooth and Aggressive to dial in the best power curve for better starts, better drive out of corners, better traction, or simply to better suit your riding style. Mode selection is easily accomplished without changing your hand position or shutting down the engine (as long as the engine is idling).
Twin to win
The CRF450RX’s twin-muffler exhaust system not only contributes to the engine’s exceptional power characteristics, it’s also positioned tightly to the frame’s centre to take weight off the rear end and optimize mass centralization for improved handling.
Standard electric start – with the kick-start system still installed as backup – gets you going quickly and effortlessly with the push of a button.
Transmission ratios and final gearing are unique to the CRF450RX for optimum performance on cross-country and endurocross courses. Extra-strong transmission gears enhance durability while delivering smooth, sure shifts.
Engine & Drivetrain
Liquid-cooled single-cylinder four-stroke
Bore & Stroke
96 mm x 62.1 mm
Unicam, 4 valves
PGM-FI electronic fuel injection with 46 mm throttle body
Close-ratio, five speed
#520 T-ring-sealed chain; 13T/50T
Chassis & Suspension
Showa telescopic inverted coil spring. 305 mm (12.0 in ) travel.
Pro-Link® KYB single shock with adjustable spring preload, rebound damping adjustability, and compression damping adjustment separated into low-speed and high-speed; 312 mm (12.3 inches) travel
Dimensions & Additional Information
90/90 - 21 front; 120/90 - 18 rear
Front 260 mm disc with dual-piston caliper; rear 240 mm disc
328 mm (12.9 in.)
959mm (37.8 in.)
1,477 mm (58.1 in.)
118.2 kg (260.6 lb) including required fluids and full tank of gas - ready to ride