Good out of the box ... better with a $300 pipe
We really wanted to have a true test of Yamaha's new racer for you folks by this time; after all, it's been two months since we first showed the world pictures and specs of the $6899 YFZ450. Sometimes you have to take the hand life deals you. Our hand? A few hours on a track hand-picked by the good people at Yamaha Motor Corp. Not such a bad deal, really. The day trip even came with lunch.

Setting out from the pits with talents such as Kory Ellis and Nic Granlund already circulating the track is a study in intimidation. Tentatively attacking the first few corners, we decided that while the motor is impressive on top, the bottom-end is a touch soft. Pair that with a light flywheel, and it makes midcorner stalls easy for a motocross neophyte. However, unlike its stablemate the Raptor, the YFZ has an admirably low center of gravity and a long wheelbase for good stability in corners, even with a narrow 46 inches in width. For a few laps, the supposedly MX-intended tires felt like typical roly-poly stock tires, but when aired to approximately 7 pounds, they were perfectly adequate. The YFZ flies nicely, is neutral in the air and is easy to redirect midflight, perhaps due to its super-low weight (a claimed 350 pounds dry).
The suspension, while no zero-sag triple-rate job as is the vogue in MX circles these days, is good. At first ride it is seemingly better than any other stock suspension. Only Polaris' Predator suspension comes close. We were able to bottom the Yamaha on flat landings with only a bit of bounce. With some dialing for conditions and weight, it'll do a competent job on the most demanding track. After a few sessions on stock machinery, the boys in blue pulled us into the pits for a little hop-up. As we watched, they mounted GYT-R pipes to a few of the machines, popped off the airbox lid and rejetted the carbs. Then they sent us back to the track. The machine was transformed.
Although the YFZ was no slug in stock form, it's wheezy in comparison with one that has these simple mods. The big difference is in the bottom-end. The pipe-equipped quad simply explodes and pulls hard all the way to redline. With all this newfound torque, everything about the Yamaha gets better. It's easier to ride, easier to set up corners and get on the gas sooner, easier to jump doubles, and it even seems lighter in the air, though that's probably just an illusion.
Why such a big difference? Thanks to our friends in Washington, D.C., all ATVs sold must produce less than 82 decibels. Thankfully, Yamaha's engineering department took this into account at the design stage and worked closely with its accessory division to develop parts that will unleash the motor's full potential with a few small changes. The slip-on pipe ranges from $300 for aluminum to $550 for titanium, with head pipes also available.
Stay tuned for a full test, along with a few interesting surprises for our newest long-term tester in the December issue.