Coming into the world of ATV racing, the Yamaha engineers already had a good chance of taking over the market. From the first YFZ450 to the latest, they have proven a point and let the world know that greatness is at hand. Tucked in the hills of Union South Carolina there would be a mystical creature named “Big Buck” and little did this evasive horned mammal know but there in the same land this day was the fierce blue competitor called Yamaha.

Getting to test the new 2010 Yamaha YFZ450X model at “Big Buck”, the home of the fourth stop of the Grand National Cross Country racing circuit, would be exciting for most anyone but knowing that this machine was specifically built to perform in this terrain, made it even sweeter.

As the years have passed since the release of the YFZ450 there has been speculation of further adapting this machine to make it more suitable for tight woods and various climates or altitudes straight out of the box. The evolution of the YFZ450 would change once again in the fall of last year to introduce the YFZ450R. The R however was really better for Motocross-style racing.

All New for 2010

• For the ATV riders who need a machine that can dominate the tight GNCC® race courses…look no more, the YFZ450X is here! Boasting many similarities with the YFZ450R, the X version is more compact for tight trails, race course, and woods riding.
• Fatigue can sometimes be a racer’s worst competition. That’s why the YFZ450X’s designers made this ATV so comfortable. It boasts racer-friendly ergonomics with plenty of room to hang off in the corners, and the seat is padded just right to be more comfortable regardless of riding position. Handlebars are 4-position adjustable, too, so every rider can choose the best position, and the throttle has been designed for all day comfort.
• This 449cc engine uses a titanium five-valve cylinder head technology, with a camshaft designed just for this machine to deliver abundant low to midrange torque for performance where you can really use it to take the lead – while still maintaining a super strong top end to let you pull away from the pack.
• The YFZ450X incorporates Yamaha Fuel Injection for precise fuel delivery. With big 42mm Mikuni® throttle body and 12-hole injector, this system provides exceptional atomization of the fuel for maximum power. The system also includes ISC (Idle Speed Control) for easy, reliable start-up and warming.
• This ATV is designed to make race prep easy. Body panels come off easily for service; there’s no need to remove the battery or other components to get the fenders off. The aluminum frame is bolted together, rather than welded, for maximum durability. And the oil tank is integrated with the crankcase so it’s easier to service the engine.

Engine:

• The fuel-injected 449cc engine has superb power characteristics. Power delivery is smooth and strong off the line with lots of low and midrange where you need it.
• The crankcase holds a crankshaft that’s ready to handle the increased balance ratio, as well as a counterbalancer for superior vibration control. The crankcase also houses the oil tank, which helps to centralize mass for unmatched handling and makes maintenance easier.
• Camshafts are designed to maximize the torque available in the low and mid ranges.
• Fuel injection uses a 12-hole injector that provides exceptional atomization of the fuel for maximum combustion efficiency and power delivery. The system also uses a big, 42mm Mikuni® throttle body and includes ISC (Idle Speed Control) for easy, reliable start-up and warming.

Chassis/Suspension:

• The chassis is very spacious, allowing room for even an aggressive racer to move around, and the ATV’s body panels that the rider contacts during operation are of a special, softer plastic material for greater comfort. The seat is narrow in the front, yet wide and padded in the rear to provide a more comfortable ride, even when hanging off on the side of the seat in a turn.
• ProTaper® handlebars are mounted on 4-way clamps for exceptional adjustability. There are two sets of holes in the handlebar crown, and eccentric clamps so the rider can choose the standard setting, 10mm or 20mm forward, or 10mm back.
• The wheel has been redesigned, with the inner lip rolled in. This increases the rigidity, allowing a reduction in weight while maintaining strength.
• Foot pegs are a generous 2.6 inches wide, something riders will appreciate every time they want to get up on the pegs, with good kick-up on the ends for solid footing.
• The frame is aluminum for lightweight, except for the frame member under the engine. Here tensioned steel is used for its combination of strength and thinness. This allowed the designers to sit the engine lower overall for excellent mass centralization for unmatched handling. The frame is bolted together, rather than welded, for maximum durability.
• The front frame is noticeably narrow at the A-arm mounting points. This dramatically reduces changes in camber as the long A-arms travel through their full range of motion. The front 44mm KYB® shocks have Kashima coating for smooth operation with superb bump absorption and excellent anti-bottoming characteristics. The 9.4 inches of wheel travel means this racer is up to even the most challenging tracks.
• The rear swingarm is crafted of strong, gravity-fed aluminum, and it’s matched to a fully adjustable 46mm KYB® piggyback shock absorber for excellent handling. Rear wheel travel is 11.0 inches for comfort even on tough terrain.
• For excellent stopping ability, YFZ450X features dual front hydraulic disc brakes and a trick looking, lightweight wave-type rear rotor.

Additional Features:

• The throttle lever requires low effort, and it’s very comfortable to use. That means less fatigue during all-day riding.
• The instrumentation is all business. The discrete panel on the fender in front of the rider gives vital indicators about low fuel, coolant temperature, check engine, and neutral gear via a straightforward LED display.

SPECIFICATION

MSRP*
$8,499 (Team Yamaha Blue) Available from September 2009

$8,499 (White/Red ) Available from September 2009

Engine

Type: 449cc, 4-Stroke Single, Liquid Cooled w/ Fan, Titanium 5-Valve DOHC

Bore x Stroke: 95mm x 63.4mm

Compression Ratio: 11.6:1

Fuel Delivery: 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 Adjustment

Chassis

Suspension/Front: Independent double wishbone, w/Kashima coated piggyback shocks, High/Low speed compression, rebound and threaded preload adjustment, 9.4-in travel

Suspension/Rear: Cast aluminum swingarm w/piggyback High/Low speed compression, rebound and threaded preload adjustment, 11.0-in travel

Brakes/Front: Dual Ventilated Hydraulic Disc, Twin Piston

Brakes/Rear: Wave Style Ventilated Hydraulic Disc, Twin Piston

Tires/Front: AT21×7-10 Radial

Tires/Rear: AT20×10-9 Radial

Dimensions

L x W x H: 70.7 x 46.1 x 41.9 in

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)

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