The all-new Yamaha YFZ450X replaces the YFZ450 and is designed specifically for tighter technical trail riding.
Powering the 450X is the 449cc Single housed in the 450R Yamaha ATV. Sourcing a five-valve cylinder head, the fuel injected mill pumps gas through a 42mm Mikuni throttle body and 12-hole Denso injector. The X gets EFI settings “specifically designed for those situations unique to technical woods riding.”
The YZ450X carves tight trails and confined terrain with a 46.1 inch girth, 2.7-inch narrower than the 48.8 inch 450R. On top of being skinnier, Yamaha brags an “optimized” suspension for technical terrain. The front A-arm is 44mm shorter, as are the KYB shocks, which are 426mm long versus the 462mm units on the 450R. The rear swingarm and fully-adjustable 46mm KYB shock take care of suspension out back.
The chassis alterations promise to “allow the YFZ450X to soak up bumps while also allowing the rider great handling through tight, technical terrain.” The changes to the X also cut five lbs too, at a claimed 400 lbs wet – dropping the weight thanks to the suspension changes and updated wheels. Wrapped on the new hoops, now more rigid with the seam of the wheel rolled inward, are Dunlop radial tires (21-inch front, 20-inch rear).
The rest of the 450X spec sheet is nearly identical to the 450R. The same no-weld cast aluminum frame completes the chassis. Dual hydraulic disc front brakes and single rear rotor team are pinched by dual-piston calipers on both YFZs. The 2.6 gallon tank, 4.5-inch ground clearance, 31.9-inch seat height and 50-inch wheelbase are also identical – not to mention the $8499 MSRP.
Yamaha expects the new YZ450X to be available September 2009. A special Bill Balance edition of the YFZ450X is expected in October, with an extra $300 getting special graphics, wheel and shock colors, GYTR bumper up front and Number-1 plate commemorating Balance’s numerous GNCC Pro ATV Titles.
2010 Yamaha YZF450X Specs
Engine: 449cc, 4-Stroke Single, Liquid Cooled w/ Fan, Titanium 5-Valve DOHC
Bore x Stroke: 95mm x 63.4mm
Compression Ratio: 11.6:1
Fueling: Yamaha Fuel Injection (YFI), 42mm
Ignition: Digital TCI: Transistor Controlled Ignition
Starting System: Electric
Transmission: 5-Speed Manual Clutch
Drive Train: 2WD; Sealed O-Ring Chain, Eccentric
Front Suspension: Independent double wishbone, w/Kashima coated piggyback shocks, High/Low speed compression, rebound and threaded preload adjustment, 9.4-in travel
Rear Suspension: Cast aluminum swingarm w/piggyback High/Low speed compression, rebound and threaded preload adjustment, 11.0-in travel
Front Brakes: Dual Ventilated Hydraulic Disc, Twin Piston
Rear Brakes: Wave Style Ventilated Hydraulic Disc, Twin Piston
Front Tires: AT21x7-10 Radial
Rear Tires: AT20x10-9 Radial
Dimensions: 70.7 Length x 46.1 width x 41.9 Height
Seat Height: 31.9 in
Wheelbase: 50.0 in
Ground Clearance: 4.5 in
Fuel Capacity: 2.6 gal
Wet Weight: 400 lb
Lighting: Dual 30W Krypton multireflector Headlights and 3.9/0.5W LED Brake light
Warranty: 6 Month (Limited Factory Warranty)
MSRP: $8,499 Available from September 2009