2017 Yamaha YZ450F

Introduction

• Same unique motorcycle with some subtle changes.

Since its inception in 2010, the reversed cylinder head, rearward slanted engine designed Yamaha YZ450F has obtained a lot of mixed reviews, especially in the pro ranks. In the years following a redesign in 2014, more and more riders have become accustomed to the feel and handling as Yamaha continues to tweak the design. With spring forks and a potent engine, many learned to adapt to the unique bike as it progresses.

Changes

• Small but effective changes.

After receiving some big changes last year, the YZ450F saw very few for 2017. The main changes increase the reliability of the already durable Yamaha. A new countershaft oil seal and oil strainer are the biggest changes along with different rear brake disc material. Dunlop’s new Geomax MX3S tires are now mounted on the bike and the air cleaner cover obtains recessed dzus fasteners. Finally, new graphics round out the changes Yamaha employed to the 2017 YZ450F.

Power

• Very powerful motor.
• Strong hit that continues to build.
• Good shifting and clutch actuation.
• GYTR power tuner allows for easy tuning.
• Launch control is better for slippery, hard pack starts.

Yamaha is no stranger to making horsepower with this motor. The YZ has been in a very happy place with a very responsive low end with plenty of hit and snap and then a continually building pull that revs out plenty far and just fast enough to be one of the most exciting 450cc motors out there. The reversed layout of the cylinder head is a keen design to make power easily with the very straight and downdraft intake tract and the extra length they are able to get out of the exhaust system by routing it around the cylinder before exiting out the back. Additionally the intake noise that is in your face gives the bike an even more visceral riding experience.

Still living in the kickstarting age, the YZ fires easy hot or cold. FI has brought not only simplified kick starting but throttle response and a crispness that is far superior to any carburetor ever. There is no bog or hesitation ever and the Yamaha is spot on in stock and standard form. Plus riders have the option to easily tune the fuel and ignition within a range through the GYTR Power Tuner--one tool every YZ owner should own.

On the bottom at low RPM, the YZ has only a little flywheel effect--not as much as some but more than others for sure. Once the throttle is cracked it doesn’t matter, there is power and torque but moreso a relatively aggressive punch. It is something that heavy riders and faster riders who can use this snap really benefit from. The mid-range is potent and here we feel the YZ450F has more throttle to rear wheel drivability and control through the middle than any other bike out there. Then onto the top and and just hang on. It may not make the most power on a dyno but try and hold the bike to the throttle stop and complain. It revs out and rarely hits the limiter before it is time to male a shift.

Shifting is decent and the clutch has control and feel while still taking a fair amount of abuse. For a cable clutch it is really good but very few of our riders abuse it. The on-the-fly adjustability is easy to use and makes getting a good feel and bite very easy. Gear ratios are just fine though we have heavier riders who really like the bike with an additional tooth on the rear sprocket. Like most bikes we find that if there is any decline in the shifting performance it is a great indication that you need to change the motor oil.

Some of our riders who prefer a smoother power delivery tend to fight with the YZ a little, mostly in the handling because the aggressive motor can make the the bike a handful in the turns. Here is where the GYTR Power Tuner really comes in handy. In a matter of minutes and easily done the power can be tamed with some additional fuel and less ignition advance, see the photos to see the maps we used. Additionally we tried a GYTR heavier flywheel. This really helped in conjunction with the less aggressive maps. When we tamed the lower power it made the bike just a little bit more prone to stalling while being way easier to ride in the turns. The flywheel really eliminated that but it also added a little more smoothing of the delivery. In reality it felt like the flywheel gave the bike more traction and let our picky rider get way more comfortable on the YZ. The flywheel does not make the bike in the least bit sluggish and it isn’t hard to bring back any response with hotter ignition settings on the tuner.

The YZ comes with launch control for the start. It is a little different feeling than most other systems in how it feels and we would only use it on concrete start pads or very slippery and hard surfaces. But we’d also suggest practicing with it to get use to how you use the throttle with it on versus with it off. After we played with the launch control, we made less mistakes off a concrete start pad.

Suspension

• Good bottoming resistance.
• Excellent spring fork.
• Shock adapts well with adjustments.

If there has been an area where the YZ has shined lately it has been in suspension. It has stayed with conventional springs in the air fork era. Since its redesign in 2016, the YZ has been known as a sharp turner, maybe too much for some especially in a world where the bikes winning the comparisons were less about turning and more about stability. 100mm is the suggested ride height for the 2017 YZ due to a slightly lighter rear spring from years past. For the average weight rider, the YZ is more in line with how other bikes feel. But for those heavier on the weight scale it has made the bike less adaptable without the correct spring, it rides lower.

Luckily the fork is excellent and does not disappoint. It has the best plushness in any conventional spring fork plus it works like we know and understand--even with very good bottoming resistance. It seems to use the stroke well and if anything is very active under most conditions.

The YZ allows the rear wheel to move a lot and pretty freely. At the same time the bike amazingly has the stroke you need so that it isn’t bottoming or packing much at all. Most riders were able to go a bit stiffer on both the compression and rebound settings and comfort and confidence went up. Some riders found there was a lot of movement on the mid-speed jumps but faster riders thought this let them fly lower and faster instead of higher.  

The fork is excellent as well and drew few complaints. It can easily take some additional compression damping without getting harsh and is good on bottoming. More on the handling front, we had a 185-pound rider who really loved a one spring rate lighter front fork spring and a slightly higher oil level to get some better feel going into turns and in mid turns and still have great bottoming resistance too. It was a balance adjustment that could not be achieved with adjusting the ride height or with the high-speed compression adjustment. The spring was the trick that really worked without any downsides and may have been a reaction to being used to the character and feel of air forks on so many other bikes.

Chassis - Handling

• Sensitive to motor and suspension changes.
• Several ways to adjust for added comfort.
• Stable at high speeds.
• Adjusting the ride height remains critical.

As much as the suspension on the YZ450F is tied to the chassis setup, so is the motor and it’s setup. As sensitive as it is, the throttle can overcome a lot of the handling characteristics, or amplify or negate them. The YZ is a very adjustable bike and maybe to its own fault, as we were playing with everything for each rider and came away with a few different combinations, just like last year.

The tuning of the chassis, small changes to even the use of thicker engine mounts, all plays into this feel that Yamaha feels is an advantage for most riders and we’d have to agree. The more stable ride of the YZ will definitely appeal to a larger group of riders. For some, the sharpness of the steering isn’t what it once was. This feeling, in our experience, is the lower footpeg positon coming into play with the stiffer chassis.

The YZ’s ride height is critical and using a standard setting in the 100mm range as a starting point is a good plan. Then the rider needs to decide if he wants better turning (tighten up the spring or add high-speed shock compression--even better go lighter on the front fork spring) or more stability (do the opposite) and fine tune from there. It is pretty simple but takes time and testing.

During testing we struggled at times with both higher-speed chop in turns and other times turning in and in the middle of the turn when getting on the power. Yet when you have the chassis setup properly, it is a simple suspension click or two away from being fixed.

In the air, the YZ has a neutral feel. It feels looser than the previous 2015 bike when off the ground but it will not challenge the lightest feeling bikes for those that like to get very aggressive in the air. Some of that may be the wider looking front of the YZ, especially to those not familiar with the Yamaha. Yet on the ground the YZ acts as one of the lighter feeling bikes. Rider control through the footpegs is excellent with a slightly heavier feel through the bars side-to-side. On our scale the bike was 248 pounds with a full tank of gas.

On the older YZ, sometime the bike just told you to slow down when the track conditions went from bad to worse. Now there isn’t such a change in the way the bike acts when it is getting beat. Last year we found switching to Dunlop's MX3S from the stock MX52 helped the bike stick to the ground better, now Yamaha has done that for you. This is really the only change you will feel between 2016 and 2017.

Lacking a gas cap it is easy to get way forward on the YZ and this helps turning but there is also a visual aspect of the bike that tells you it is wide. Some riders feel they can’t get forward as much as they’d like. The footpegs changes from last year affect the handling more than you’ll ever feel them in the rider compartment. The larger front brake is now commonplace on MX machines and heavier 450s for sure can use the strength and along with that control. The Yamaha has this covered. A Pro-Taper handlebar has a bend that most find comfortable and the top clamp allows four positions for rider preference. Just like last year we reported a funny sensation--the bike gives a feel that there is something loose on it--as if a shock linkage bearing is worn. We checked everything and the bike is tight. We feel this is a very friction-free engine that is now more tightly clamped in the chassis and you can feel a different type or frequency of vibration. It may also be the chain, which stretches pretty consistently and needs adjustment every few rides.

We should also mention that when we changed the engine character with the Power Tuner it really changes the way the bike handled. Riders who like to slide and turn the bike with the throttle liked the stock setting and found an even more aggressive map could have as much effect as adjusting the ride height. A more tame map allowed those who liked a front wheel turning bike to appreciate the weight the YZ can put on the front wheel and then still pick it back up with more throttle and higher RPMs.

The indented plastic on the airbox cover eliminated any of our riders knocking the fasteners loose. Rear brake draggers will likely have better life out of the rear rotor but none of our testers abuse the brakes so we did not notice it.

Conclusion

• Appealing bike to a wide range of riders.
• Yamaha durability.

The 2017 Yamaha YZ450F is a great bike for most riders. It isn’t the lightest 450 but that is about the worst thing you can say about it. For many it is the most powerful depending on what part of the throttle or RPM range they ride the bike in. Even higher up the list--the praise of the suspension--its familiarity and ease to dial in for most riders. We have been impressed with the durability of the Yamaha in the past few years, in a time when riders are asking their bikes to last longer, the YZ’s continue to improve. And if you don’t like Blue, well there is a White one too!