If all it takes is a new handlebar, some slight internal suspension adjustments and revised jetting inside the carburetor to keep a bike on top of the heap, that bike had better be really good. Oh yeah, and changing the head size on a few bolts as well. The YZ250 had the class covered last year, and we guess Yamaha was as hard-pressed deciding how to improve the bike as we were.
It doesn't matter either way, because Yamaha hit the nail on the head with each of these changes, refining a really great bike. The standout to all of our riders was the motor. The YZ pulls from the basement to the top with an insanely crisp, smooth and linear powerband that made a fan of anyone who rode it whether they possessed a four-stroke bias or not. The new jetting completely eliminated the midrange detonation and made it even crisper than we remembered. Along with its quickness and controllability, it has a suddenness and responsiveness that four-strokes envy. And the clutch easily adds amplitude to the delivery. Spacing of the gearbox ratios is spot-on, and shifting is decent-just remember this bike craves clean tranny fluid and a properly adjusted clutch.
The changes to the fork tube's diameter and internal valving yielded a very plush ride, one that was mirrored by the shock's performance. The YZ retains its very light feel, especially through the handlebar. While jumping, it flicks and whips so easily we want to make comparisons with 125s. It falls into turns effortlessly and tracks exceptionally well for a bike that never feels as planted as a thumper. If anything, it seems the springs were more heavily taxed (and at the end of their ability to get proper ride height with a 180-pound rider aboard), and the bike exhibited an extreme lightness on its feet. It was a little dicey when accelerating, and that prompted us to tighten the rebound slightly at both ends to allow the bike to settle better. And the additional flex of the ProTaper bar was welcome, especially on sharp hits.
Fear not, the two-stroke isn't gone. And for most of us, this YZ's performance doesn't give up anything because of its engine type.
Opinions
For the past few years, the Yamaha YZ250 has been my favorite two-stroke motocrosser. The '07 model is a refined '06 at best, but that is OK with me. The engine is a notable improvement. It pulls stronger and cleaner from lower in the rpm range, and it seems to have less violence to the hit. I'd still need to open up the riding position and install stiffer springs for it to suit my size and my riding preferences, but this bike is worth the effort. Now, if Yamie just made it in a 300...
Karel Kramer/6'1"/210 lb/Senior Intermediate
Ten years ago, when there was no such thing as a really good four-stroke, you could barely comprehend that there are now riders fearing the death of premix-burners. Hey, the blue guys still sell enough two-strokes to keep them around and keep them current. The two-stroke might not be a manufacturer's first priority any longer, that's all. KTM is all-in with a totally revised 250 SX, and going head-to-head with this YZ is the only way to tell how good it is going to be.
Jimmy Lewis/5'10"/180 lb/Vet Pro
Specifications
MSRP: $6299
Claimed dry weight: 212 lb
Actual weight (ready to race, no gas): 219 lb
Seat height: 38.1 in.
Seat-to-peg distance: 19.6 in.
What's Hot
Great throttle response.The detonation is gone.Really light and agile.What's Not
Not as planted as four-strokes.You have to shift a lot.