2021 Yamaha YZ450F

[Hugh Janus]

2021 Yamaha YZ450F (Yamaha/)

Ups

• Torquey engine character that makes it an absolute monster on the track<br/>
• Confidence-inspiring suspension that allows for easy adjustment (if needed)<br/>
• Unparalleled stability that “encourages outside lines and higher speeds”<br/>
• Free and best-in-class tunability via the Power Tuner app

Downs

• Loud exhaust and airbox noise<br/>
• Cable clutch could be replaced with hydraulic unit<br/>
• A taller seat can improve uncomfortable rider triangle

Verdict

Although it may sing a loud tune from the exhaust and airbox, the Yamaha YZ450F’s engine, suspension, and chassis sing in great ride-quality harmony.

2021 Yamaha YZ450F (Jeff Allen/)

Overview

To determine the best full-size motocrosser for 2021, the annual Dirt Rider shootout was conducted, in which the Yamaha YZ450F took second place on the podium yet again. The reason for its continued success is that it is widely regarded for its engine power, predictable handling, and comfortable suspension. Its ergonomics, however, is one of the departments that slightly holds it back.

2021 Yamaha YZ450F Monster Energy Yamaha Racing Edition (Yamaha/)

Updates for 2021

Mechanically, the Yamaha YZ450F remains unchanged for 2021. It does feature changes with blue number plates, black fork guards, and new radiator shroud graphics where the Monster Energy Yamaha Racing edition features a factory team-inspired graphics and black plastics.

Pricing and Variants

The Yamaha YZ450F is slated as one of the most capable motocross bikes right off the showroom floor, and at the dealer showroom you will find it has an MSRP of $9,399. The Monster Energy Yamaha Racing Edition is also available at an MSRP of $9,599.

Powertrain: Engine, Transmission, and Performance

Equipped with a 449cc, liquid-cooled, DOHC four-stroke engine, the Yamaha YZ450F is fast. To find how much power the YZ450F produces at the rear wheel, we tested it on our in-house dyno where 53.1 hp was recorded at 9,700 rpm and 32.7 pound-feet of torque at 7,400 rpm. Test rider Tanner Basso stated, “It has lots of overall power and torque, revs very quickly, and is aggressive yet rideable. Also, the Power Tuner app allows for endless fuel delivery and ignition timing tunability.”

Tunability through the Power Tuner app, first introduced in 2018, offers a best-in-class tuning capability that we found useful in smoothing the engine’s power delivery.

In regard to engine-braking we noted in our first ride that it “might be a touch more noticeable in comparison to other 450s, but for the most part, you ride the YZ450F in a lower rpm and it’s not a significant factor.”

The five-speed transmission is modulated with a cable clutch that has an easy pull and doesn’t fade. Our test riders would like to see the cable replaced with a hydraulically actuated unit.

2021 Yamaha YZ450F (Yamaha/)

Handling

The KYB suspension of the YZ450F provides the most comfort and plushest feel in the class. They are easily adjustable and work great even for a variety of rider abilities and weights. Base settings are excellent and barely require further adjustment after sag is set. Thanks to its phenomenal suspension, our test riders felt that they could push the bike harder than most of the others in the comparison.

A fairly compliant frame offers stable handling and excellent comfort, but it falls short of the Kawasaki KX450 in terms of flex.

Although it is one of the heaviest bikes in the comparison at 248 pounds, the stable handling “encourages outside lines and higher speeds.”

2021 Yamaha YZ450F (Jeff Allen/)

Brakes

Stopping the motocross bike is a 270mm disc/Nissin two-piston caliper pair out front and 240mm disc/Nissin one-piston caliper out back. In our First Ride Review, test rider Allan Brown wrote, “The Yamaha brakes have a distinctly progressive feeling. The front is easy to modulate and the rear is progressive, making it easy to drag the brake without locking up the rear wheel.”

Fuel Economy and Real-world MPG

Fuel economy figures are currently not recorded, however, the YZ450F has one of the smallest fuel capacities in the class at 1.6 gallons, the same tank size as the Kawasaki KX450.

Ergonomics: Comfort and Utility

The cockpit of the YZ450F is particularly roomy, especially with the handlebar positioned in the stock position. In order to reduce headshake and improve steering, our test riders preferred to move the handlebar to the rearward holes instead of the stock’s forward setting. Good news is this change did not make the cockpit feel cramped.

The rest of the ergonomics and rider triangle does feel off though. This is because the thin, low, and slightly uncomfortable seat has a noticeable dip that makes movement around the machine more difficult. Yamaha’s Tall Seat option could significantly improve these issues.

Electronics

A map switch offers two different engine maps. The YZ450F is also equipped with launch control. As stated above, tunability is easy to use thanks to the Power Tuner app, which connects to the bike via Wi-Fi.

Warranty and Maintenance Coverage

The Yamaha has a comparable 30-day factory warranty.

Quality

Although there are some gripes in terms of ergos and comfort, the YZ450F takes “best in class” for a variety of categories including suspension, engine tunability, and engine character.

2021 Yamaha YZ450F (Jeff Allen/)

2021 Yamaha YZ450F Claimed Specifications

MSRP:	$9,399
Engine:	449cc, DOHC, liquid-cooled single-cylinder four-stroke
Bore x Stroke:	97.0 x 60.9mm
Transmission/Final Drive:	5-speed/chain
Fuel Delivery:	Mikuni electronic fuel injection w/ 44mm throttle body
Clutch:	Wet, multiplate, cable actuated
Engine Management/Ignition:	N/A
Frame:	Aluminum bilateral beam
Front Suspension:	KYB Speed-Sensitive System (SSS) coil-spring fork, fully adjustable; 12.2 in. travel
Rear Suspension:	KYB shock, fully adjustable; 12.5 in. travel
Front Brake:	Nissin 2-piston caliper, 270mm disc
Rear Brake:	Nissin 1-piston caliper, 240mm disc
Wheels, Front/Rear:	Spoked wheels
Tires, Front/Rear:	Dunlop MX33; 80/100-21 / 120/80-19
Rake/Trail:	27.0°/4.7 in.
Wheelbase:	58.3 in.
Ground Clearance:	13.0 in.
Seat Height:	38.0 in.
Fuel Capacity:	1.6 gal.
Wet Weight:	245 lb.
Contact:	yamaha-motor.com

Cycle World Tested Specifications

Seat Height:	37.9 in.
Wet Weight:	248 lb.
Rear-wheel Horsepower:	53.1 hp @ 9,700 rpm
Rear-wheel Torque:	32.7 lb.-ft. @ 7,400 rpm

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