Kawasaki updates 2019 KX450F with race-derived technology

Completely redesigned and lightened motocross machine ready for competition

Kawasaki has unveiled the 2019 KX450F. This brand new dirt bike joins Kawasaki’s illustrious KX line as a new iteration of its flagship motocrosser — with advanced technology and input directly derived from the Japanese brand’s factory race team.

It’s got a slimmer aluminum frame, a new stressed-member engine, a revised swingarm, new suspension, and a lot more upgrades that truly propel the KX450F into a new generation. The 2019 KX450F is the first motocross bike of Kawasaki’s to get an electric starter. Its brand new four-stroke, water-cooled, DOHC 449 cc thumper is now lighter — tuned for more peak power and a flatter torque curve. Its single cylinder has been offset forward by 8.5 mm for less mechanical loss, hence more efficiency. A lithium-ion battery helps shave more weight.

Kawasaki World Superbike engineers have given the new XK450F finger-follower valve actuation — which reduces friction and affords a more aggressive cam profile, larger titanium valves (40 mm intake and 33 mm exhaust), an increased rev limit, and better performance at high rpms. Its lightweight bridged-box piston design is the same used by the Monster Energy Kawasaki race team. The fresh engine also receives a downdraft intake manifold and a new 12-hole fuel injector for its new 44 mm throttle body.

The thumper is mated to a close-ratio, five-speed transmission with a new hydraulic clutch; the latter is another first for a Kawasaki dirt bike. The 2019 KX450F features button-activated launch control and, once again, Digital Fuel Injection (DFI) couplers with three terrain settings: standard, hard, or soft. The handheld XK FI Calibration Kit is available as an optional Kawasaki Genuine Accessory, for tuners that want direct programming access to the bike’s ECU — eliminating the need for a laptop. It is PC compatible, stores up to seven preset maps, and together with the DFI couplers can be used with the engine running.

The 2019 Kawasaki KX450F gets 49 mm Showa coil-spring forks with A-KIT technology, an adjustable Showa Compact Design rear shock, Uni-Trak rear suspension linkage, a 270 mm front disc with a dual-piston caliper, and a larger 250 mm rear disc with a single-piston unit. It has a dry weight of 105.4 kg, a fuel capacity of 6.2 L, and a seat height of 955 mm. Kawasaki has set the MSRP to $9,299.