It's not 2008. In fact, it's not even close. But that hasn't stopped Yamaha from delivering a nicely updated YZ-F to the hungry world of motocross. Welcome to the first test of the first bike from the future (of next year).The 2007 Yamaha YZ250F was and is a solid bike. Consistent power with a smooth delivery kept it in the middle of almost all of our testers' rankings during shootout season. The handling and suspension were in the same boat, with most pilots happily riding the bike through the bumps and chop with some complaints on initial turning and settling. That's why we used it for a hop-up story (see "Stock to Sweet," August '07); it was easy to get along with stock but even easier to boost up to its potential for the more aggressive, faster racer. Almost before the ink was dry on that story, Yamaha was ready to deliver the '08, and after a week of testing, here's what we really think.The single most noticeable improvement to the YZ250F on the track is the super-squeezing piston. By swapping last year's 12.5:1 compression-ratio piston with a 13.5:1 unit, Yamaha boosted power on the bike where it matters. The once mellow delivery is now enhanced with a healthy mid snap and newfound grunt. The bike is more than awakened from last year-from the bottom to upper mid, but still retains great tractability and stability while accelerating. Sometimes more power can damage a ride if it's not delivered properly-not so in the YZ-F's case. On top, the power behaves a bit like the '07, encouraging you to shift up to drop the revs to the reborn bottom and mid. Also, the piston skirt has been narrowed 4mm to drop some weight and reduce friction against the cylinder. These motors have been bulletproof for us in the past, and we expect the new piston to continue that trend... we'll see in a hundred hours or so. All in all, we love the new power and think it just might be the missing link the stock Yamaha needed.Speaking of links, the new YZ-F features a revised linkage ratio under the shock that is helping keep all those new ponies in line out of the gate. There are other suspension changes as well. Stiffer springs front and rear, internal modifications to the compression circuit in the shock and shorter, lighter outer fork tubes all aim to improve the ride.In our initial tests, the handling of the bike is almost mirroring last year's. The in-the-pit complaints of the bike resisting initial cornering movements are still mumbled, and we've experienced some unsettling in the rear over high-speed rolling bumps in corners. Basically, the bike likes to stand up. Sag adjustment is ultra-important as always, and we've found this bike wants a bit more than the recommended 100mm (our best has been between 103-105mm). This sounds like a small change, but its effect is huge. We're satisfied with the stiffer springs front and rear and will just keep looking for the perfect setup. One component of the handling is greatly improved: the tires. Bridgestone teamed up with Yamaha and developed the all-new M403 front and M404 rear that come mounted on this '08 YZ-F. They're solid. We rocked them on our '07 Stock to Sweet bike and were very impressed. We're working on dialing in the whole handling package for shootout time, so stay tuned (we know it's hard to be patient, but try).The rest of the changes are basic yet nice. The carburetor features updated jetting; with a new double-taper needle the motor runs as clean as we've ever felt from a stock bike. The footpegs are now gigantic. With a 10mm-wider platform, they require an adjustment period for the shifter foot but are a nice pad nonetheless; they're also 5mm lower to open up the cockpit a bit. Internally, the bike's clutch finally has a single style of fiber clutch plate used throughout. Now you only have to buy one type, not two of one kind and seven of another. Thank you Yamaha, you're getting easier to maintain.As the first one to the party, the '08 YZ250F now has to wait around for its competition before it can really see how it stacks up. If you're anxious to see if its head start will turn into a win, join the club; we can't wait for shootout time!2008 YZ250F
MSRP: blue, $6249; white, $6349
Weight: ready to race, no gas: 217 lb
Claimed dry weight: 204 lb
Seat height (above the pegs): 37.0 in.Opinions
After turning our 2007 YZ250F into a race bike, it's ironic that the new model is almost a mirror image of the machine that we came up with. In comparison to last year's almost tame motor, the 2008 is a snappy, powerful rocket that can be taken to the line right off the showroom floor. The motor takes off with a decent amount of torque, but it really shines in the upper-mid section of the revs, right where the '07 threw in the towel. I prefer 250Fs when they can be ridden in the high end of the midrange but with extra power waiting in the top portion in case I get in trouble, and this describes the new Yamaha perfectly. As for handling, I had some issues with the bike lifting when going into braking bumps and standing up in rutted turns, but both of these issues were mostly worked out by lowering the rear end and softening the fork a click. While the Yamaha is not yet a perfect turner, the new model feels smooth and yet again compliant, no doubt thanks in part to the new linkage setup. The updated footpegs are pretty trick as well, but the fact that they are lower made the shift lever feel slightly long. Considering every issue that Yamaha addressed from last year's model, I was pretty disappointed that Big Blue stuck with the same shape on the upper corner of the radiator shrouds-these things go straight down the top of my boots with annoying consistency. However, Yamaha made up for this with its oh-so-sweet custom ProTaper bar bend. All in all, I thought the 2007 Yamaha was a solid bike, and this new 250F is one heck of an improvement!
-Chris Denison/5'10"/155 lb/IntermediateThe new blue machine looks the same as last year's, but when you twist the throttle, you feel a big difference. It has the same linear power curve we liked in our shootout (April '07) but with more ponies! The motor is much more competitive. The braking system is also strong, with a very controlled and powerful front brake. Being the brake dragger that I am, I was happy to find that the rear brake proved strong and consistent until the end of my moto. The suspension felt plush and controlled. It really tracks great on the small braking and acceleration bumps, and the fork has good bottoming resistance and decent movement throughout the stroke. The shock was also stable and worked best on acceleration bumps. The old YZ-F reared its head in the new model as the '08 was still trying to stand up on me in the turns, but with the sag set a little lower than 100mm, the bike seemed to settle in better. Dropping the sag also cured a wallowing feeling I got on high-speed sweeping turns that had rollers in them. The YZ-F is still a great overall package, and for 2008, it comes with a much more competitive motor.
-Ryan Orr/5'10"/175 lb/Pro