2014 Yamaha YZ450F | Motocross Motorcycle Test

2014 Yamaha YZ450F | Motocross Motorcycle Review

The 2014 Yamaha YZ450F is a completely redesigned motocross machine from the ground up compared to the previous edition. The engineers at Yamaha aimed to create what they call The Ultimate YZ by combining ease of cornering and a usable power band, with a chassis that is lightweight and compact.

The 2014 YZ450F’s all-new engine is still the basic design—a DOHC motor with a four-valve head and rear-canted top end–but received several revisions including a new piston, cylinder head, intake camshaft, intake and exhaust valves, and a wrap-around exhaust system. Down below, there’s a new wet sump crankcase, shift mechanism, and transmission ratios.

The new bottom end has is a wet sump design with slightly smaller in oil capacity (last year’s oil tank is gone), easier shifting, and a more usable third gear. The blue machine also has a new airbox with nearly triple the capacity of the old design, and that means increased power and reduced intake noise. As a bonus, you can now get the to YZ450F’s airbox without removing the fuel tank.

The new chassis consists of a new aluminum Bilateral Beam frame that moves the front wheel 10mm closer to the center of the bike. The inverted fully adjustable Kayaba air-/oil-separated spring forks and Speed-Sensitive System damping return for 2014, receiving a few small revisions with increased rigidity of the outer tubes and a new polishing process for the inner fork tubes. The layout of the rear shock has been relocated to accommodate the new exhaust and fuel tank.

Having ridden the previous generation YZ450F, I was anxious to hop on the new bike and see how the new steed held up on the track. The first thing I noticed was the strong, yet smooth, powerband. The engine is stronger than before, and boasts lots of bottom end power and transitions into the mid-range without ripping your arms off. Lots of tricks contribute to this, including an exhaust pipe that wraps around the cylinder, and features three different diameters for optimum flow.

In addition to the bottom end and mid-range, the over-rev is equally impressive. With these engine characteristics, the YZ450F can be lugged around the track in a taller gear, or kept higher in the rev range, depending on each rider’s ability and preference.

I found that I could ride most tracks in 2nd and 3rd gear comfortably, and could even ride some of the wider turns in 3rd gear not having to click a gear down from one part of the track to the next. The YZ450 is designed to extra torque from 3rd gear through 5th. This makes the bike more manageable in the lower two gears, while increasing the pull in the upper cogs.

If you feel the need to adjust the power, the accessory GYTR Power Tuner will please the tinkerer. You can’t use it to get more overall power than stock, but you can adjust the power curve to your liking.

The YZ’s suspension is certainly one of my favorite parts of the bike. After setting the suspension up to my weight and riding style–no sag in the back, as I weigh 130 pounds–I felt right at home on the blue machine. Front and rear, the suspension is confidence inspiring.

Coming up a bit short or long on any of the bigger jumps at Milestone MX Park (Riverside, Calif.) and Pala Raceway (a former AMA National track in Pala, Calif.) didn’t prove to be anything to sweat about. The 2014 Yamaha YZ450F feels much more nimble in the air than the ’13. In addition to soaking up the bigger impacts, the YZ is very plush over the braking bumps as well.

When cornering, the YZ450F settles nicely into ruts and felt solidly planted once in the corner. However, it did seem to push the front end at times when entering flatter, bowl turns, even with the great emphasis on cornering in the new design. I found that getting my weight farther forward and sitting up near the tank seemed to alleviate this problem.

Extra weight on the front end causes no stress as the front axle diameter has been increased and the new triple clamps are more rigid. With that rigidity, Yamaha went with rubber mounted handlebar mounts to cut vibration. Even with the rubber mounting, the front end didn’t feel vague.

Overall, the 2014 Yamaha YZ450F is much improved over last year. The completely new bike has strong, yet smooth power, incredibly plush suspension over small chop and hard impacts, and a nimble, easy to chassis–you can ride anywhere from the trail to the track. In an intense sport where there is always room for improvement, Yamaha’s “Ultimate YZ” 450F is one step closer to being the ultimate motocross bike.

Photography by Don Williams

Location: Milestone MX Park, Riverside, California

Helmet: Vemar VRX9
Goggles: Oakley Airbrake MX
Neck protection: Leatt-Brace Pro-Lite
Jersey, gloves, and pants: Moose Racing Racewear M1
Boots: Sidi Crossfire 2

Andrew Oldar is sponsored by Moose Racing.

2014 Yamaha YZ450F Specifications
Engine…449.7cc liquid-cooled DOHC 4-stroke w/ 4 titanium valves
Bore x stroke…97.0 x 60.8mm
Compression ratio…12.5:1
Fueling…Yamaha Fuel Injection, Keihin 44mm TCI
Transmission…Constant-mesh 5-speed; multiplate wet clutch
Front suspension…KYB Speed-Sensitive System, inverted fork, fully adjustable, with 12.2″ travel
Rear suspension…KYB fully adjustable single shock w/ 12.4″ travel
Front brake…Hydraulic single disc brake, 250mm
Rear brake…Hydraulic single disc brake, 245mm
Front tire…80/100-21 Dunlop MX51-FA
Rear tire…120/80-19 Dunlop MX51
Length x width x height…85.6″ x 32.5″ x 50.8″
Seat height…38.4 inches
Wheelbase…58.3 inches
Ground clearance…13.2 inches
Fuel capacity…2.0 gallons
Wet weight…245 pounds
Colors…Team Yamaha Blue/White; White/Red


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