YFZ450R set a new standard in a sport ATV class that had fallen behind the times in terms of technology and performance. If you were a hardcore racer before the YFZ, you had to heavily modify a sport machine for racing or extend the life of the decades old Honda TRX250R two-stroke. Both options were costly and miles behind the tech being used in the
motocross world. That all changed with the 2004 YFZ450R - a truly high performance racer with a modern four-stroke mill and a chassis to match. Ten years on, Yamaha has given this segment-defining ATV a host of updates meant to keep it on the top on the podium at the local tracks and national championships alike.
While the 2014 YFZ450R does not look too different from the 2013 models, Team Blue has gone over the ATV with a fine tooth comb to give it more power, better handling and more user friendly features. From the bodywork to the motor to the suspension, not much was left untouched by the Tuning Fork Company to elevate this racer’s game, and the result is greater than the sum of the parts.
Right from the first crack of the thumb-throttle it’s clear that power has been improved. It’s been a couple of years since I’ve ridden a YFZ450, but even my hazy memory tells me there is more on tap. Altered camshaft profiles, a high compression ratio, revised ECU settings and a new 42mm Mikuni throttle body provide the extra oomph despite the addition of an air induction system to cope with stricter emissions standards. Power comes on strong from the bottom, hits hard in the mid-range and then continues to pull right up to the rev-limiter. In stock trim the YFZ’s engine was able to get my 220-pound frame over all but a couple of the jumps at The Ranch
And when I didn’t quite make it over, the revised suspension was able to soak up the worst case-jobs without needing medical attention for my ankles or wrists. Bottoming resistance was excellent from the 3mm longer front shocks and reworked spring and damping settings for both the front and the rear. Even more impressive was the plushness on small chop, ruts and square-edged bumps. In the past I’ve always had to back out the compression clickers to try and get some smoothness, not so this year. Even when the track began to deteriorate towards the end of the day, the ride was still compliant and allowed me to ride longer and harder than I expected.
The suspension settings also translated into better feel when cornering, as the new Maxxis
Tires were able to stay in contact with the dirt. The front tires had excellent feel and grip, while the rears allowed for controlled slides and solid straight-line acceleration. The YFZ corners fairly flat with proper body positioning, but with the stock height tires some off-camber/high traction situations do cause the inside to lift. Yamaha’s decision to use a 21-inch front and 20-rear tire gives the YFZ the all-round performance, but I would change to a smaller diameter 20-inch front and 18-inch rear to combat tire roll and lower the over center of gravity.
Getting into the corners while hard on the rear brakes was phenomenal thanks to a first-for-production-ATV slipper clutch. The assist/slip clutch removed the tendency of the rear wheels to hop coming into a corner while downshifting and braking.
An added bonus of the slipper clutch is a light pull at the lever due to the assist function. The plates are forced together on acceleration via interlocking ramps and this allows for only three springs to be used. While I did enjoy less fatigue thanks to the feather-light pull, I did notice that as the plates lock up the feel is diminished. On a MX track it’s not a huge issue but it could be in slower point and shoot cornering on the trial such as that in GNCC racing.
Yamaha didn’t stop at just adding more power, suspension and handling to the YFZ450R, the rider’s compartment was also tweaked for more comfort and function. The rear fenders have been remolded to allow the rider to slide off and on the seat easier with less of step between the two. While I never had a complaint before, it is now easier to get back onto the seat after finishing a corner. Up front, the tank plastics cover more of the frame and have a smoother transition to the front fender to keep the rider’s knee from banging to the frame as well as being easier to slide forward. Four-way adjustable handlebar clamps gives a comfortable reach to the bars for any size rider. Personally, I found the as-shipped position to my liking for MX duties, but I would prefer a taller bar if I were to hit the trails or desert.
After a day at the track with the 2014 YFZ450R I would have to say that once again Yamaha has elevated the sport ATV game. It may not be as revolutionary as the 2004 introduction, but it is much improved from the previous model. With more power, a slick slipper clutch and better suspension performance the rest of the ATV field will be playing catch up yet again.