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At first glance the 2017 Yamaha YZ250F could be mistaken for the ’16 model, except for the BNGs. But think back to that time when your mom said, “Don’t judge a book by its cover.” Looks can be deceiving since the Blue Crew made changes to the suspension, frame, engine, intake, and transmission, just to name a few. What follows is an overview of the major changes and how they were felt out on the track after our initial day of testing at Glen Helen Raceway.

Engine: More Meat From An Already Beefy Bike

Yamaha has continually refined their modern (backwards cylinder) YZ250F in a calculated and careful manner, and we don’t blame them – why risk messing up a good thing? Yet, for 2017 the YZ250Fs motor and intake sees a bunch of small tweaks that add up in the end. A straighter intake, new air funnel, new throttle body joint, and redesigned cylinder head ports all make it easier for the motor to gulp more air, quicker and with a wider diameter mid pipe, it can spit out those spent gasses easier as well.

The goal was to gain mid-to-top power and we can say that they hit their mark. Over the last few years the YZ250F’s engine character was exciting, snappy, quick revving, and pretty strong yet left us wanting a little more on top. It is like Yamaha was in our shootout meetings because that’s just what they gave the ’17 bike. We could noticeably pull each gear longer and had an easier time climbing Glen Helen’s massive hills than on the ’16 bike, which we rode back-to-back. Plus, we didn’t notice any drop in bottom to mid power either. In fact, across the board the new blue machine felt like it had more torque.

Shifting: Smooth Operator

With a new bushing on the shift arm, different actuator arm angle and length, and smoother shift grooves on the shift drum the YZ-F should shift quickly and with minimal effort. But honestly, this wasn’t a complaint of ours on last year’s bike and hoping back and forth, neither of our testers could really feel a difference in the bikes’ shifting action or feel. We can say the clutch felt easier to pull by a small amount, but again, this wasn’t a complaint that we had of the ’16 model. Lastly, the shift pedal was stiffened up to address some complaints of flex.

Chassis: Tight, Toned, and Taut

We hear the words “rigidity balance” a lot when talking about chassis, but that isn’t marketing speak – there really is a balance of flex and stiffness which has no easy answer. When you stiffen one thing, it puts more pressure on something else. This is the case on the YZ250F with its new stiffer frame sections by the footpegs. Beefing up this area, as well as changing the engine mounts for more stiffness, transferred more energy to the forks which, in turn, got stiffer fork tubes, yet a lighter spring rate. This all sounds confusing, but Yamaha is chasing that elusive carrot of a precise handling bike with comfortable yet high-performing suspension without giving up compliance and stability. Did they do it? Well, one day isn’t enough to definitively say, but we think the YZ250F is now a bit easier to turn and has a light, nimble handling feel that makes the bike feel flickable and overall, less heavy. It also felt more responsive to rider input when changing lines at the last minute.

Suspension: We Aren’t Blowing Air

The YZ250F retains its smile inducing KYB SSS (Speed-Sensitive System) with coil springs in both fork legs. As we said before, the ’17 bike gets one spring rate lighter springs, a result of chassis being more rigid. Steve Butler, Yamaha dirt bike guru, explained in the presentation that, in testing, they found that the added frame stiffness transferred more energy into the forks, but they were feeling stiffer because they were flexing so much that they were binding up. Therefore, the fork tubes were stiffened to reduce the fork leg flex and the spring was lightened to get some comfort back in the front. Interestingly enough, both our pro level tester and vet-speed guy felt that the fork was stiffer than last year’s bike. This suited the pro tester very nicely and he didn’t touch a clicker all day. The slower tester actually went three clicks softer on compression to get a little more feel and comfort in the front. Yamaha still recommends 100 mm of sag which is a little higher than most OEMs but it works for the Yami. It does give the bike tall feeling overall but it feels balanced front to back.

(By Sean Klinger, via dirtrider.com)