Everything aligned for Yamaha in the 250 class in 2015. In National MX, Jeremy Martin had the number-one plate. In the press, the production YZ250F won virtually every shootout. In dealerships, the Yamaha was the best-selling 250 four-stroke of the year. All the sine waves peaked simultaneously, but just two years earlier Yamaha was all but forgotten in the 250 class. The YZ250F of 2013 had become a rolling anachronism, little more than a placeholder to remind people that Yamaha had pioneered the class. The chief problem was complacency. Yamaha’s engineers were on top of their game in 2001, but somehow didn’t notice when the rest of the industry caught up and moved ahead.
Now the challenge for Yamaha is to not let that happen again. The 2016 YZ250F is here, primed to take advantage of all the hype and success. It faces a revitalized 250 class and has a moderate number of updates and changes. In order to stay on top this time, Yamaha engineers have to move forward, and they know it.
In 2014 the redesign of the YZ250F was massive and radical. That was when Yamaha tilted the motor’s top end rearward and turned the head around so the exhaust port was in the rear. The battle cry was mass centralization, which is the idea that the heaviest parts of the motorcycle should be in the center. The YZ also got heavier that year with the coming of fuel injection, but it didn’t gain as much weight as most other 250Fs, and so it remained the lightest bike in the class.
Most years, between major model changes, Yamaha makes some universal adjustments to both the YZ250F and the YZ450F: new bar clamps, brake pads or whatever. This time, the approach was different. The 450 got one set of changes and the 250 got another, as if there were two different groups of test riders and engineers. It makes sense. Even though the two bikes had the same configuration and many of the same parts, they had different problems that called for different solutions. Thus, the 450 got major frame and chassis changes, while the 250 primarily got motor changes. The most significant of those is a new flat-top piston that, when combined with a new shorter piston pin, is 10 percent lighter. That’s somewhat amazing, considering that the YZ piston was already very light. Both the piston and pin got a new DLC coating for less drag too. The flat-top design came about after expensive computer analysis, studying what happens in the combustion chamber immediately after combustion. There’s a primary shock wave that tumbles in one direction, which is good, but there’s also a secondary, counter-rotating shock wave. The new piston shape minimizes that secondary shock wave. The lesson here is that the days of try-it-and-see engineering are gone, and engine designers are going deep into theoretical realms to find the smallest improvement.
The crank is new. It’s stiffer, has a different balance ratio, new thrust washers and the rod has a new heat treatment. The balance ratio is all about vibration, and a new counterbalancer addresses the same issue. The crank oil sprayer was reconfigured, too, and Yamaha says the result is a 10-percent decrease in piston temperature. Third, fourth and fifth gears have a different radius on the dog corners this year, and the clutch judder spring is gone. The clutch hub is said to be more precisely made, and there are changes in the shift mechanism. Then, of course, there are electronic changes. The ignition rev limiter still allows the motor to spin all the way up to 14,000 rpm, but the way it acts on the motor is different, making for a less abrupt shutdown. The fuel mixture is also leaner at places on the 2016 EFI map.
Yamaha elected not to give the 250 the stiffer frame that the 450 got, or the change in steering offset, but it did get a softer rear shock spring (56 N/m to 54 N/m). There were also valving changes at both ends, but Yamaha is stubbornly hanging on to the KYB SSS fork and its two conventional coil springs. We’re happy with that. We’re also pleased with the move to a 270mm front brake rotor.
LIFE AT 14,000 RPM
Let’s start off with what [isn’t] different. The YZ250F is as fast as ever. The bike makes excellent low-end power, and on top it still screams like a Stuka. The motor is the bike’s strongest single asset, and it remains that way. It has no weak points anywhere along the way to its impressive power peak. There are usually trade-offs involved with a 250 motor; if it makes good torque, it won’t rev and vice versa. The Yamaha is strong everywhere, but its top end is what gets the job done. As a result, you often find yourself flirting with the rev limiter, and that brings us to the biggest improvement of the year. Last year it would run strong right up to the point where it wouldn’t run at all, and riders ended up in that max-rpm zone of sputtering and hiccuping that was annoying, if nothing else. Now the bike ends its run more gracefully. It still refuses to go past the same redline, but there isn’t as much electronic chaos.
In the 250-class rankings we already know that the Yamaha’s chief competitors will be the KTM and nearly identical Husqvarna 250Fs. The KTM had the most peak power last year, and we know it has more for 2016. We also know that it had a lot of ground to make up when it came to low end and midrange, so we’re very anxious to get both bikes head to head to see who the new horsepower king will be. Honda and Suzuki also found more power, so everyone is gunning for the Yamaha, and it will be interesting to see who comes out on top when the smoke clears. But for right now, we still love the Yamaha motor as much as ever.
Number two on the Yamaha hit parade is back as well. The suspension is the standard of the class. The KYB fork in particular represents the pinnacle of coil-spring technology. It’s relatively plush on small bumps, has great bottoming resistance and never does anything spooky. Our only real criticism is that it’s aimed at the high end of the class. Its springs are a touch stiff for younger, less experienced riders. That, obviously, isn’t an issue for pneumatic forks. The air fork on the Honda CRF250R matches the Yamaha fork in performance (if you know how to set it up properly) and can be adjusted to work for anyone (again, if you know how to set it up properly). The truth is, modern air forks aren’t that difficult to adjust, but it is one more layer of maintenance that we didn’t have to deal with a few years ago.
Yamaha’s decision to soften up the rear end makes sense. Like the front, the rear was a touch soft for the average man. We suspect the main motive, though, was to make the front end feel more secure. This is in response to a complaint that was common on the 450, but only a few riders mentioned it on the 250. The 2016 YZ250F still handles pretty much the same. It’s great most of the time, but it does like aggressive cornering with lots of throttle. It’s not a point-it-anywhere bike like the Suzuki RM-Z250. The Yamaha requires a little more planning and setup when you approach a difficult turn.
BETTER AND BETTER
We’re going to send a nice thank-you letter to Yamaha for the larger front brake rotor. It’s still not a KTM brake, but stopping power is better, nonetheless. Other items are as good as ever; the clutch pull is super light and has a good feel. Shifting is excellent, although neutral is a little harder to find, and the overall fit of the bike is good for most riders. It comes with the handlebar in its second, most-rearward position (of four possible options), which is good for medium-sized riders. And the bike is still light, at 222 pounds without fuel. It used to be the lightest in the class, but Honda and KTM have since joined in at the exact same weight. That’s a reoccurring theme in this class. The Yamaha is currently on top, and the 2016 YZ250F is good enough to stay there as the year unfolds.
But it won’t be easy.
• Excellent overall power
• Love that coil spring fork
• Good clutch, shifting
• Great tires
• Durable graphics
• Brakes are better, not the best
• Gas-tank access is weird
• Stiff suspension setup
• Likes aggressive cornering technique
YAMAHA YZ250F SPECS
Engine type: Four-valve, DOHC 4-stroke
Bore & stroke: 77.0mm x 53.6mm
Fuel delivery: Keihin EFI
Fuel tank: capacity 2.0 gal. (7.5 l)
Lighting coil: No
Spark arrester: No
EPA legal: No
Running weight, no fuel: 222 lb.
Wheelbase: 58.1″ (1475mm)
Ground clearance: 12.8″ (325mm)
Seat height: 38.0″ (965mm)
Tire size & type:
Front 80/100-21 Bridgestone M404A
Rear: 100/90-19 Bridgestone M403
Front: KYB, adj. reb., comp./
Rear: KYB aluminum piggyback, adj. prld,
hi & lo comp., reb., 12.4″ (317mm)
Country of origin: Japan
Suggested retail price: $7690 (60th Anniversary Edition)