2017 Yamaha YZ450F


Words: Broxy | Photos: Alick

In whatever form it takes – for moto, enduro or cross-country – Yamaha’s 250F is a hit with everyone, but what about its bigger brother, the YZ450F?

From the outside looking in, the YZ250F and YZ450F might look the same, but there is way more than what meets the eye. Of course, we knew that would be the case with the power, but not so much with the handling. Make no mistake, side by side, the two bikes are hard to tell apart. When you take a closer look, the normal signs of a bigger bike such as a larger barrel and fatter header pipe are easy to see, but one difference that isn’t so easy to spot is the traction control button on the MX1 machine.

By taking a closer look, it is also revealed the biggest change for 2017 that only the 450 received, one which keeps the 250F waiting once again.
Over the years it has been exciting to see the major Japanese brands continually updating the standard components on their machines to the point where you almost can race these machines at a high level straight out of the crate. But there has always been one thing that lets them down… and that is where the rubber meets the track.
For 2017, Yamaha made an interesting call with the tyre choice for the premier class motocrosser and going for the softer compound, which many had been asking for. This year, the YZ450F sports the newly released Dunlop MX3S tyre, and we are pleased.
The MX3S tyres feel like the real deal, and I hope that the other bikes catch up soon. Harder compound tyres will last longer, but how long do you want to ride a set of tyres that are holding you back from the start? Finally, with just some small suspension tweaks, you can actually take a standard Japanese machine to a big race and confidently line up oat the gate.

Muscle Mass

It is no secret that the big Yamaha is in no need of extra ponies on the racetrack; so much that Chad Reed said that he didn’t need a special engine for the MXGP, as what is essentially the standard motor was more than enough. While he might not have been up with the front-runners, but if what is basically a standard engine gives enough power for him, most of us will be also plenty happy.
Having the airbox directly above the motor gives such a direct route for the air to flow that horsepower is never going to be an issue.
Last year, what was interesting was how the changes Yamaha made to the valve lift did not give it more peak horsepower, but it didn’t need more. Instead, it increased the bottom end grunt, which improved how it transitioned into the midrange.
On the track, there is no doubt that this engine has plenty of bark when you want it. Even without the clutch, second gear can be used through the tightest of turns and can also power you a long way down the next straight. Along with high horsepower, if you want it, there is also plenty of over rev to use.
If you want a little extra pop to lift the front over a hole, you will never be caught short on the YZ450F. It isn’t as snappy as the pre-2014 YZ450F used to be though, which your arms will be thankful for.
On Kiwi tracks, in order to save my arms from pumping up too soon, I do tend to shift to third fairly early. The YZ450F doesn’t wheelie too much, which means it just requires less of a vice-like grip on the handlebars, if you shift early. And the rougher a track gets, the better this style of riding becomes.
But the real beauty of this power is the abundant torque, combined with useable bottom end power that doesn’t punish you too much for the inevitable misdemeanor that your throttle hand can produce. That means you don’t need to hover on the clutch too much, either, another reason why your arms will be glad for that low down forgiveness.
From an easy down low and ripping up top, that’s what I call fun.

Big Bear

What surprised me the most was how the bigger bike even handled nicer that its smaller sibling. Yes, the YZ250F was fast, but the suspension felt like it needed more running-in time, unlike the 450 that was forgiving from the get-go. At medium pace, the suspension and frame combined beautifully to actually soak up the bumps, with no sign of harshness on the terrain that I was powering over.

Some people have found the older version to be quite vague under acceleration, but this bike felt great with no bad feedback through the handlebars, whatsoever. This may have been helped by the torsional stiffening, which was made to last year’s bike, with a thicker frame around the swingarm pivot and beefier head stays. Yet, this year, the 250 also received those updates; so that doesn’t explain the added forgiveness this bike had under acceleration.
I wondered how much of it was simply due to the torque that this engine possesses, pulling the suspension through each bump, rather than bouncing off them. Really, the bikes are just not that dissimilar in weight to produce that kind of a difference in handling.
Since Yamaha revamped the bike in 2014, the real test of this bike has always been under braking where that lively feeling usually returns. This can be noticed especially when pushing it hard through choppy braking bumps that push the frame past its comfort level.
“Refined stability when aggressively entering corners,” is how Yamaha put their goal in last year’s machine, and the bigger bike felt happier through these bumps than it used to be as well.
I was impressed.
From there, my straight-line confidence could really get in to gear. These bikes are more stable at high speed than any other brand, helping you get the most out of the impressive motor package. I know people that are on the YZ450F for this very reason and I can see why. You can really get on the pipe, especially at a place like Pirini Motorbike Park, with its fast trails and open motocross track.

The Nitty-Gritty

If you were in the market for buying a bike and inclined to make lists, there are three things you might like to consider putting on the lists of cons.
The trade off for the extra stability mentioned above is always going to come at the cost of “turnability” in the tight stuff, so it depends what you value the most. It will certainly get you around the corner, but it is just a little less willing to turn as sharp as some other brands.
An example of this is an open berm – where it might not be easy to simply turn down and square them up at will – or flat turns where the front might want to push ahead, instead of naturally going the direction you want it to. In ruts and low berms, it is at its best, only showing a vague heavy feeling.

Although, there is another area that the buyer will take note of, which is the width of the current YZ450F through the frame and shrouds. While it is narrower than it used to be, it feels wide because of how it flares quite suddenly, as your knees travel into the sitting position. I honestly don’t think most buyers will even notice this, but I do wonder whether Yamaha will have a go at making it a bit narrower with the next generation frame and engine. It wouldn’t be a surprise to see electric start options available in the near future, too, since the technology is already there with the FX machines, so we will just have to wait and see. The obvious problem with that is the added weight, so I will be interested in how far the Blu Cru goes in giving it a diet in the future without sacrificing reliability.
Really, the only other factor to consider are the sound effects coming from the front of the bike, which, again, would be noticed by most riders – and you do get used to it, too.
So, those could be the cons.
Although, when it comes to the lists of pros, you might want to make sure you have plenty of room to write them all down.

Near the top of the list is the quality of manufacturer that Yamaha is known for being. Examples of this came through on the 2016 model, with even more mods for ’17, such as small details like the gear-stop lever receiving roller bearings and then stiffer springs and supports on each side for the next year. Last year, Yamaha changed the dog shape on the gears for more precise shifting and made some mods to the water pump impellor. The only thing the engineers chose to change mechanically for 2017 was a new material for the rear brake disc, just to avoid any warping that could occur in extreme conditions. All of this would tell you that the bikes are getting pretty close to perfect when it comes to reliability tweaks.
Also right near the top of the list would be the power. But there’s no need to say anything more, is there?
I could go on with the pros, but let’s just add one more, which would be the forks. Yamaha remained staunch through the craze of air forks that all other brands have tried. The KYB SSS units are undoubtedly heavier than air forks, but are often raved about for performance, which is the most important thing. Added to that is the fact that they are a set and forget unit, not needing to be checked often.
With that, long live spring forks!

Smart Bike

Before we go, it is important to tell a little bit more about the second button you see on the handlebars, which is the launch control. It is more than just another marketing gimmick, too, as this is a trick bit of kit.
To avoid the wheelies that ruin most of our starts because we have to back off the throttle, the Yamaha unit cuts the horsepower much more than most other launch control systems, which would normally seem bad. But, instead of waiting until you hit third gear before giving you full power, it will automatically give you full boost ten to twenty metres from where you launched. This will happen once the rpm and throttle position sensors have convinced the ECU that you have the situation under control and it will switch off when you hit third gear.
This is one launch control system that I could imagine using.
Instead of making the bike feel annoyingly slow off the gate, it made it easier for me to be more aggressive on my launch.

Without the launch control, the front wheel would lift like a rodeo bull, requiring either a lot of clutch work or less throttle. Yet, with the button flashing, I could get the throttle on full without my left index finger having to act the superhero on the clutch over those first few meters.

Don’t get me wrong, it still wanted to wheelie, as the acceleration is intense and required plenty of care – just because an ECU thinks you have it sorted enough to give you full beans, that doesn’t make it true. It just isn’t quite so nutty off the initial launch, all without losing the benefit of full power for the second half of your time in second gear, which means that I would actually consider using it.

That basically sums this bike up, too: it can be wildly fast without losing the control necessary to confidently maximize your potential.
What surprised me the most was the lack of liveliness that I have found on these bikes in the past.
This YZ450F is a nice bike, and doesn’t have to try hard to impress.

2017 YAMAHA YZ450F

PRICE: $13,999.00

Engine Type: 449cc liquid-cooled DOHC 4-stroke with four titanium valves
Bore x Stroke: 97.0mm x 60.8mm
Compression Ratio: 12.5:1
Fuel Delivery: Keihin Fuel Injection 44mm


Transmission: Constant-mesh 5-speed; multiplate wet clutch
Front Suspension: KYB Speed-Sensitive System, inverted fork: fully adjustable, with 315mm of travel
Rear Suspension: Fully adjustable single shock with 315mm of travel
Front Brake: Hydraulic single disc brake with 270mm rotor
Rear Brake: Hydraulic single disc brake with 245mm rotor
Front Tyre: 80/100-21 Dunlop MX3S
Rear Tyre: 120/80-19 Dunlop MX3S


Length: 2164mm
Width: 825mm
Height: 128mm
Seat Height: 966mm
Wheelbase: 1475mm
Ground Clearance: 325mm
Fuel Capacity: 7.5L
Wet Weight: 112kg