RIDING THE NEW YZ TWO-STROKES

It seems weird, but the best-handling dirt bike in the world hasn’t won a pro MX race in over 10 years. The Yamaha YZ125 is the handling champion of the dirt world; the only people who might argue that point are those who have never ridden one. But, there hasn’t been a 125 National Championship since 2005. And for various reasons, Yamaha hasn’t been a factor in that class for even longer—probably dating back to Kevin Windham in 1997. Likewise, the Yamaha YZ250 is still here, still doing some things better than any other motorcycles, but doing them very quietly.
A LITTLE ATTENTION, PLEASE
For 2015, the keepers of Yamaha’s corporate wallet decided to give a little love to the two-stroke line. For years, Yamaha’s unofficial policy toward the YZ125 and 250 was: “You’re lucky they’re still here.” Actually, it’s true. We were lucky. The sales figures for the YZ two-strokes were unimpressive. That’s the real reason Honda, Suzuki and Kawasaki left the segment. New four-strokes cannibalized sales of the two-strokes. Many people pointed out that this was a self-fulfilling prophecy, claiming that if the two-strokes had received the same amount of development, they would have been more competitive both on the track and in the showroom. Fair enough, but there wasn’t enough money for both programs, and the two-strokes were left behind.
Now Yamaha is at least acknowledging that the YZs deserve attention. The two-stroke faithful would be delighted with even a morsel, because the 125 and 250 haven’t seen many updates since 2007, and they both look a little like vintage racers sitting brand new on the showroom floor. But, realistically, the bikes simply couldn’t be redesigned from scratch. There wasn’t enough in the budget. So, an allowance was set for a few big changes. The first was suspension. The YZ four-strokes had speed-sensitive KYB forks that were said to be among the most expensive of all OE front-suspension units. They would be easy bolt-on changes but might go unnoticed, so new plastic was added to announce that the two-strokes were indeed different. In the end, the 2015 YZ two-strokes got one change in function and another in form. That’s not bad.
Both the 125 and the 250 motors are still pretty good, even if they aren’t the fastest in their respective classes. The fact that they are unchanged isn’t necessarily bad. Yamaha has the technology for direct-injection two-strokes in its marine division. The HPDI V Max 175 is a V6 two-stroke that displaces 2596cc, produces 175 horsepower, and is clean enough to earn the California Air Resource Board’s two-star rating. When the dirt market is ready, Yamaha engineers probably reason that will be the next motor change. It would be a waste to redesign a conventional two-stroke motor that is on the way out. For now, we’re delighted with the changes Yamaha did make.
YAMAHA YZ125
Riding the 2015 YZ125 is pretty much like riding any YZ125 from the last decade, except it’s new and has a new fork. It’s a great experience. In case you don’t know what’s so good about the little YZ, it can be summed up in one phrase: it makes you good. It’s so light that it makes you feel like you’re super-rider. The bike weighs 200 pounds without fuel, so if you go from an average 250F to the YZ125, it’s like taking off a backpack filled with about four bowling balls. That’s why people say it’s the best-handling current dirt bike. You can have your way with it. Any 125 might be in contention for the honor, but what always made the Yamaha special was its suspension. Even before the new front end, it was the best in its class. With the addition of the KYB speed-sensitive fork, it gets better in some situations. You might not notice much of a change under most conditions, but the new front end definitely feels more stable at the extreme ends of performance. It handles sharp, rapid hits very well and is capable of over-jumping the biggest jumps without dire consequence.
Still, with all other things being equal, two-stroke suspension suffers when compared to four-stroke suspension. This isn’t about the fork or shock; it’s more about the bike’s ability to track in a straight line. A 250F with the same chassis will handle whoops better and hold a line. It isn’t a huge deal on most tracks, just ones with poor traction and lots of chop. So while a YZ125 can still be called the world’s best-handling motorcycle, there has to be an asterisk and a footnote: “Not on all tracks; not with all riders.”
As for the motor, the YZ125 was generally held to be the best in class 10 years ago. Since then, it has only been surpassed by the KTM 125 and, of course, the KTM 150, which is often lumped into the same group. The KTM has more on top, but the Yamaha is competitive down low. The Yamaha’s bottom end makes it easier to use, but you still have to shift. Upshifting will take care of itself, but the real trick is knowing when and how far to downshift. You can stretch the powerband only so far with the clutch. A good 125 rider knows how to stir the gearbox. It’s difficult at first, but young riders moving up from an 85cc two-stroke will think the powerband is as wide as Texas. That’s the YZ125’s real target audience, anyway. The only problem is that those young riders might not stay with the 125 long if they want to race. There aren’t enough other 125s to race with, and as good as the Yamaha is, it doesn’t have the sheer power to be competitive with 250 four-strokes.
YAMAHA YZ250
Just like its little brother, the YZ250 is a handling phenomenon, but it makes more power and is heavier. If you ride a 125 and think, “Boy, if only I could have something that handles this well but with 10 more horsepower,” you’re expecting too much. Horsepower is the sworn enemy of handling, and the YZ250 has a lot of horsepower. It takes a little more effort to toss around, and when you twist the throttle hard, there can be consequences. Okay, so it’s not a 125 with open-class power, but it is light and fast, and that goes a long way on most tracks. Unlike the 125, which has to race exclusively with other 125 two-strokes, the YZ250 can mix it up with four-strokes and have a reasonable chance of success. When a YZ250 and a modern 450 are side by side trying to get to the inside line of the next turn, the YZ250 will win eight times out of 10. And it should. It can stop faster than any 450, and that means it can hold the throttle open longer. The trick is getting side by side with the 450 in the first place. A four-stroke has a natural tendency to find traction, whereas the YZ250 has to hunt for it.
Traction is the YZ250’s weakness. It makes plenty of power and weighs 20 pounds less than a typical 450. If it hooks up, the YZ can get on the gas early and come out of the turns hard. If not, it will lose its momentum quickly. The new fork is a clear improvement on the 250. It’s a particular advantage in the Yamaha’s contest against the other 250 two-stroke, the KTM 250SX. The KTM has more power than the Yamaha. It responds quicker down low, pulls harder through the middle and makes more on top. It’s not a huge gap, but it is noticeable. But as with any two-stroke, the KTM struggles with traction and the ability to track straight through rough stuff. The Yamaha already had a suspension advantage that has only grown. Most riders still prefer the Yamaha on the track.
There probably aren’t that many motocross racers looking to the YZ250 or 125 anyway. They have come to be regarded as general-purpose dirt bikes for anywhere. You can ride them off-road, take them to the track during the week and put them away for months at a time. There’s no battery to go dead, and even the carb never clogs up because premix resists that urge. You don’t get an electric starter or a hydraulic clutch like you do with premium European two-stroke trail bikes, but you aren’t asked to pay for those items, either. The YZ250 sells for $7290 and the YZ125 is $6390. They already offered the most value in the dirt bike world, and they still do. Now they just look better doing it. o
YZ125 HIGHS
• Handles fantastic
• Super light
• Excellent suspension
• Light clutch
• Good brakes
• New look

YZ125 LOWS
• Limited appeal
• Must race with other 125s
• Some riders just forgot how to do it

YZ250 HIGHS
• Excellent handling
• Excellent suspension
• Finally, a facelift
• Weighs 20 pounds less than a 450
• Cheap to own

YZ250 LOWS
• Motor left unchanged
• Not as powerful as it could be
• Sometime struggles for traction
YAMAHA YZ125
Engine type: Liquid-cooled, power-valve two-stroke
Displacement: 124cc
Bore & stroke: 54.0mm x 54.5mm
Fuel delivery: 38mm Mikuni
Fuel tank capacity: 2.1 gal. (8.0 l)
Lighting coil: No
Spark arrestor: No
EPA legal: No
Running weight, no fuel: 200 lb.
Wheelbase: 56.8″ (1443mm)
Ground clearance: 14.4″ (366mm)
Seat height: 38.4″ (975mm)
Tire size & type:
Front: 80/100-21 Dunlop MX52
Rear: 110/90-19 Dunlop MX52
Suspension/travel:
Front: KYB, adj. reb., comp./11.8″ (300mm)
Rear: KYB aluminum piggyback, adj. prld, hi & lo comp., reb., 12.4″ (315mm)
Country of origin: Japan
Suggested retail price: $6390
Manufacturer: www.yamahamotorsports.com
YAMAHA YZ250
Engine type: Liquid-cooled, power-valve two-stroke
Displacement: 249cc
Bore & stroke: 66.4mm x 72.0mm
Fuel delivery: 38mm Keihin
Fuel tank capacity: 2.1 gal. (8.0 l)
Lighting coil: No
Spark arrestor: No
EPA legal: No
Running weight, no fuel: 217 lb.
Wheelbase: 58.3″ (1481mm)
Ground clearance: 15.0″ (381mm)
Seat height: 39.1″ (993mm)
Tire size & type:
Front: 80/100-21 Dunlop MX52
Rear: 110/90-19 Dunlop MX52
Suspension/travel:
Front: KYB, adj. reb., comp./11.8″ (300mm)
Rear: KYB aluminum piggyback, adj. prld, hi & lo comp., reb./12.4″ (315mm)
Country of origin: Japan
Suggested retail price: $7290
Manufacturer: www.yamahamotorsports.com