Back in 1998, Yamaha revolutionized the motocross market with the introduction of the first modern four-stroke race-ready production machine: the YZ400F. A few years later, the tuning fork company did something similar for the small-bore class with the 2001 YZ250F. Then came a long period of incremental changes to Yamaha’s 250cc four-stroke race bike that kept the bike competitive, but didn’t necessarily make it a class leader. This was largely due to the engine remaining relatively unchanged for more than a decade. By 2013, the YZ250F was the only carbureted 250F left amongst the major OEMs.
Finally, for 2014 Yamaha decided the world was ready for another revolution (quite literally in this case) with the introduction of a fully redesigned YZ250F complete with a reversed engine (mimicking that of the YZ450F), new frame, suspension and just about everything else. After the reviews came in, the motorcycle was widely regarded as one of the most potent 250 machines of the year, offering a performance package that suited a broad range of riders and was ready to race right out of the box. Further proof of the bike’s vigor has come in recent months as pro riders Jeremy Martin, Cooper Webb and Christophe Pourcel have been regular fixtures at the front of the 250 Class in the 2014 Lucas Oil AMA Pro Motocross Nationals.
So, with all of the changes and accolades, why mess with a good thing? Fortunately, Yamaha knows it has found an undoubtedly strong package, so a little tweaking can only make it stronger. With that in mind, the 2015 Yamaha YZ250F received a small revisions that will help keep it at the front in the coming year.
For 2015, the YZ250F has revised suspension settings on the tried and true Kayaba SSS (Speed Sensitive System) forks. In the engine department, new exhaust valves improve durability and are paired with a new exhaust cam for easier starting. Meanwhile, a better lubricating piston and ECU and ignition calibration help provide more control throughout the rpm range. Other changes for the new model year include Dzus quarter-turn fasteners for easy airbox access, a 20% lighter throttle return spring, a positive roller-type gear stop lever, new embedded graphics, gold D.I.D. chain and, last but not least, black Excel rims.
A company could make diamond-studded engine cases, but if it does nothing to improve performance, who really cares? Yamaha’s changes were fairly subtle, but they are geared towards improving the bike on the track.
Hopping on the YZ250F, the ergonomics are what one should expect of modern motocross machinery: a flatter seat, comfortable frame that allows the rider’s legs to grip the bike, and adjustable bar positioning. Adding to the coziness is the Yamaha-exclusive feature of a recessed and completely covered gas cap, allowing the rider to literally sit above the gas cap with zero discomfort.
I have found the YZ250F kickstarter to have just the right orientation and shape to make starting the bike a breeze. Once starting up the machine with one easy kick and taking to the track, the Yamaha’s ergos continue to impress falling somewhere in the middle of the 250 ranks in terms of size. Some bikes feel as though they have a shrunken cockpit, while others feel stretched out and more suited towards taller riders. The Yamaha splits the difference, and can suit a wide range of users. For a 6’3” rider such as myself, I had plenty of room to move around without being cramped.
Reversed But Not Backward
If there is one major benefit that has come from Yamaha turning around the orientation of the motor on the YZ250F, it is some serious low-end grunt. When first cracking open the throttle, in a blind test (which probably is not a good idea, I’m talking theoretically here people) a rider might believe the bike to be a heavily modified race machine, due to both the sound and the low-end power. In truth, the crisp tone emanates from the airbox that lies directly beneath the rider’s head, but the power is true and undeniable.
) A gold D.I.D. chain and black Excel rims are new for 2015 as well. (Middle
) New embedded graphics are among the list of updates to the 2015 YZ250F. (Below
) In the engine department, new exhaust valves are paired with a new exhaust cam for easier starting.
On the tight Milestone MX track where the initial test took place, the initial hit is noticeable and continues onto a robust mid-range as the power just keeps on rising. There is not much room at Milestone to truly get a sense of the YZ250F’s power at high rpm. However, I did experiment with winding out the motor in lower-than-ideal gears through a few sections, and was surprised to find the bike’s willingness to continue producing horsepower beyond the revs where I expected the ponies to flatten out. In my far more extensive time on the 2014 YZ250F, the only place where I felt the performance could use some improvement was on fast straights at high rpm, as the power did tend to die off slightly. The 2015 engine and ECU updates may have helped mitigate this issue.
Get It Handled
Every manufacturer has particular characteristics that manage to permeate throughout the different years and models. For example, it is almost unheard of for a bike to transform from an understeering machine to an oversteering one between two model years.
For the YZ250F in particular, stability has never been an issue and that fact remains for 2015. Point the bike in a direction, whether accelerating or braking, and it will continue in that direction no matter the obstacles that lay in its path. Both the front and rear end of the bike will stay inline and provide a balanced ride thanks to the superb settings of the KYB SSS fork and KYB shock.
On faster, more wide-open tracks and turns, the Yamaha is exactly what a rider desires of a motocross machine: stable and planted, yet nimble and light, which is probably one of the reasons why the bike is currently leading the 250 Class National points chase. However, take the YZ250F into tighter confines and it struggles to commit to those sharper, less gradual turns. Yep, the understeer that Yamaha’s have been known for continues, although this is not an issue that is nearly as bad as it sounds.
Basically, the blue bike requires a slightly different rider technique of sitting farther forward while turning to help plant the frontend and remain in a desired orientation. When riders do not fully commit to making a turn in this manner, they are met with a wallowing, vague front wheel that can’t quite decide whether to lean over or stand upright. Of course, all of this is dependent on a rider that prefers steering with the front wheel. If you are more of a point-and-shoot type racer or one who power steers with the rear end, then you will feel right at home on the YZ250F. And right at home is exactly where the YZ finds itself on bumps of any kind, big or small.
If It Ain’t Broke…
The tested, tweaked, and re-tweaked KYB SSS fork has been standard Yamaha motocross equipment for nearly a decade. While many other companies are switching over to emerging suspension technologies, the boys in blue have chosen to stick with a traditional coil and oil fork on the YZ250F for good reason: it works. No matter the situation, whether it’s high-speed chop, rolling whoops, or just a big ol’ double, a rider can has confidence the forks will consistently provide plush and progressive action. Of course, the draw back of a regular sprung fork compared to the newer separate function and pneumatic options is the lack of quick spring-rate or preload adjustability along with added weight. However as the saying goes, “If it ain’t broke, don’t fix it,” and the KYB SSS is, in my opinion, the exact opposite of broken and remains my preferred MX front suspension in stock form.
Out back, the KYB rear shock matches the characteristics and performance of the fork, with smooth and predictable action in high-speed chop and through braking bumps. As a heavier rider, I would prefer to move to a stiffer spring as I felt the shock tended to give a little too much when seat bouncing and through acceleration bumps. Nonetheless, in stock form the shocks performance should be more than adequate for any rider falling under the 170-pound mark.
As I mentioned earlier, I spent a decent amount of time aboard the 2014 YZ250F, and felt it was one of the strongest 250F MX offerings on the market. My opinion remains the same for 2015. From the overall performance to the tool-less airbox access and stealth black wheels, Yamaha has put together an excellent 250 package. I suspect that plenty of people will start feeling the blues when the time comes to hop on a new MX steed this coming year.
2015 Yamaha YZ250F First Ride