Dirt Wheels - September 2013

better visibility and moved forward for more rider legroom. The side panels and rear fenders have been flattened out to better accept sponsor logos, and the warning labels have been relocated for better number, graphic or logo placement.

Now every YFZ450R model comes with quick-release fasteners for easy bodywork removal. No other quad on the market offers that feature. A new orange color is available, along with blue and the special-edition red option. The standard YFZ450R will list for $8599, and the SE model will fetch for $8949.

Internally Yamaha gave more power and reliability to this engine by increasing the compression from 11:1 to 11.8:1 They did this by installing a slightly longer (.25mm) connecting rod. A bigger rod bearing and new camshafts were also added. Outside, the EFI system was upgraded with a new throttle valve to give the engine a more powerful and exciting hit.

More notably, the new YFZ450R
now comes equipped with what is
known as a slipper-style clutch. Its
function is to reduce hard engine
braking, which ultimately improves
traction under braking. During accel-
eration the function holds the clutch
tighter than a conventional system for
less slipping. This should be a huge
advance in sport-quad performance.
Aftermarket companies like Hinson
have been marketing a similar sys-
tem to top-level dirt bike and quad
racers for over five years with great
success.

Suspension upgrades on the 2014 YFZ450R include a slightly longer (3mm) front shock and a slightly stiffer rear coil spring, which were both no doubt the result of extensive testing with their top racers Chad Wienen, Dustin Nelson and Josh Row. Additionally, all-new Maxxis tires were developed exclusively for the YFZ450R. The machine still comes with 20-inch rear tires and 21-inch- tall fronts mounted on 9- and 10-inch- tall aluminum wheels, respectively.

UTILITY LINEUP

A full range of Grizzly 4x4 sizes will be offered, from the compact 350 and 450 machines up to the full-size 550 and 700s (starting at $7999 and

Yamaha increased the overall width of the Grizzly 700 by installing 30mm- longer A-arms on all four corners. They also increased the amount of assistance the EPS unit provides.

changes, just as they did a couple of years ago.

The largest change to the Grizzly comes in the suspension department. Yamaha made the A-arms 30mm wider on both sides. The shock stroke was also increased by about 1 inch in the front and 3⁄ 8 of an inch out back. These changes will only be made on the Grizzly 700 and will not yet trickle down to the 550 model, even though in previous years it shared the exact same chassis.

YFZ450R

In 2014, only Yamaha and Can-Am are offering a wide, track-ready, 450cc sport quad. Suzuki is still rebuilding their Quadracer LT-R450, and KTM only sells their wide SX quads in Europe. Can-Am’s DS450X mx will be unchanged for 2014, while the Yamaha YFZ450R will get some improvements. Leading off that list is the redesigned bodywork. The front nosepiece is angled down more for