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By: Jason Giacchino

Yamaha Motorsports

2009 Yamaha YFZ450R Yamaha Ups the Ante in the 450 Class


YFZ450R

Getting Up To Speed

There is a pretty interesting trend going on in the performance segment of the ATV market these days in that each of the big seven (Yamaha, Kawasaki, Suzuki, Honda, Can-Am, KTM & Polaris) have suddenly realized that quad racers aren’t going to settle with “almost-race ready” equipment much longer. Case in point: Yamaha was already aware of the potential of their YFZ450 in stock trim but wanted to offer prospective customers an even more MX-inspired model for 2009. Enter the YFZ450R, an all-new motocross weapon that will actually share the model line with the more trail-friendly YFZ450. Sure they could have just tweaked the existing model to extract a bit more power out of its mill; but things are happening fast in the MX market of late, and Yamaha doesn’t intend to play second fiddle to the likes of the new KTM SX line or the Can-Am DS450MX. Yamaha hit the ground running with this all-new R model; and if there’s one safe bet to be made, it’s that ATV racers are finally being taken seriously at the OEM level.

We’ll begin by examining some of the differences between the standard YFZ and the new YFZ-R. Nearly three inches wider overall than the YFZ450, the stance of the new 450R now comes motocross-standard at 50 inches. The frame itself is made of lightweight aluminum, with a tension-steel bottom section that allows the engine (and rotating mass) to sit lower for mass centralization. Suspension components will offer nearly an inch of additional travel, motocross specific damping. Up front Yamaha spec’ed 44mm KYB shocks with Kashima coating for smooth operation, increased durability and excellent anti-bottoming characteristics (9.8 inches of travel). The rear swingarm is crafted of gravity-fed aluminum and matched to a fully adjustable 46mm KYB piggyback.  Rear wheel travel is 11 inches.

Additionally the new chassis allows for relocation/ rearranging of the cockpit. The goal is to create a much roomier platform, with plenty of room to hang off in the corners and to move around on in the air. ProTaper bars come stock and are 4-position adjustable too, and the throttle has been designed for all day comfort. What’s more, to counter the reputation of aluminum as being rigid and teeth chattering, the engine’s counter-balancer has been revised to further reduce vibration.

Yamaha didn’t have to look far to find a suitable power plant to stuff into their new chassis as this 449cc mill uses both the head and cylinder directly from the championship-winning YZ450F: Titanium five-valve cylinder head technology, with a specifically-designed camshaft to deliver abundant low to midrange torque while still maintaining a potent top end for those tracks that require riders to hold onto a gear until the cows come home.



Carburetor holdouts will be saddened to hear that but another machine is waving goodbye to the concept of needles and jets in favor of EFI. The YFZ450R joins a long list of performance-oriented quads to adopt fuel injection for precise fuel delivery and electronically controlled fuel management. With a 42mm Mikuni throttle body, 32 bit ECU, and 12-hole Denso injector, this system provides exceptional atomization of the fuel for maximum efficiency. The system also includes Yamaha’s Idle Speed Control (ISC) system to make for reliable start-up, warming, and dreaded hot-start performance.

Details, details… Remember the days of having to remove half a dozen fender bolts to reach your air box? Well, Yamaha wants to help you forget about that as the new 450R has been engineered to make preparations and maintenance specific to racing a snap. Body panels come off easily for service; there’s no need to remove the battery or other components to remove the plastic. Like the Can-Am DS450, the aluminum frame is bolted together, rather than welded. Also, the oil tank is integrated with the crankcase to make engine service less of a hassle.

Even the foot pegs haven’t been overlooked. The YFZ450R will feature 65mm wide stockers with kick-up on the ends for solid footing.

Interestingly, Yamaha has opted to stick with 20-inch diameter rear tires (bucking the trend of the typically considered superior 18 inchers for MX use) in the form of all new Dunlops: 21 inches front/ 20 rear.

Finally, wavy rotors for improved heat dispersion come stock all around and even the instrumentation has been relocated to a fender panel so as not to complicate the bars.

Yamaha claims the wet weight of this machine at around 405 pounds, placing it pretty close to the weight of the standard YFZ450 (which was around 350 pounds/dry).

As with any model this new and anticipated, Yamaha understandably asks that test riders come to them. As such we sent a rider up to Gorman, California to spend some saddle-time on both the trails and MX track (side note: it didn’t take much convincing to wave goodbye to the snow-buried trails and blizzard-like conditions of New York to test out in sunny California).

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