The YFZ450R is the most technologically advanced sport
ATV on the market today. It is simply the top of the
line “racing” level Sport ATV. It combines a high-tech,
quick-revving, titanium five-valve, 449cc fuel-injected
engine with a lightweight, professional-caliber cast
aluminum/steel chassis. The power/chassis combination
will make for a championship-winning machine
time and time again.
The YFZ450R is motocross ready. The weldless frame is
designed from lightweight aluminum, with a tension-steel
bottom frame that lets the engine sit lower for
excellent mass centralization. Suspension
components and settings reduce weight while
providing light, sharp handling and rider comfort.
Bodywork is designed for great ergonomics and rider comfort, with more room to hang off in the corners, and the seat shape is padded in just
the right places to improve lap times. Body panels come
off easily without tools for service; there’s no need to
remove the battery or other components to take the
The 449cc engine uses titanium five-valve cylinder head technology designed to deliver abundant power in the mid-range to top end, with more
“hit” feeling right off idle. The higher compression ratio
further improves overall engine performance.
The YFZ450R incorporates Yamaha Fuel Injection for
precise fuel delivery. With a big 42mm Mikuni® throttle
body and 12-hole injector, this system provides exceptional
atomization of the fuel for maximum power. The
system also includes ISC (Idle Speed Control) for easy,
reliable start-up and warming.
The industry’s first assist and slipper clutch on a Sport
ATV reduces clutch lever effort by about 25% for less
fatigue while at the same time increasing clutch plate
pressure for positive engagement. Additionally, this new
clutch system reduces the engine braking effect, which
allows faster cornering, particularly when downshifting,
and also allows the suspension to absorb bumps better
The fuel-injected 449cc engine has superb power characteristics. Power delivery is smooth and strong off the line with lots of midrange to top end power.
The crankcase holds a crankshaft that’s ready to handle the increased demands of the racer, as well as a counterbalancer to reduce vibration. The crankcase
also houses the oil tank, which helps to centralize mass for
unmatched handling while making maintenance easier.
Camshafts have been revised to help maximize the engine’s
impressive power output from off the line all the way up to the
The body configuration allows more room for the racer to move around during the moto. The seat is narrow in the front, yet wide and padded in the rear to reduce fatigue.
The wheels have been designed with the inner lip rolled in. This
increases the rigidity, allowing a reduction in weight while maintaining
Wheels are set motocross-spec wide, near the maximum allowable 50 inches, for great cornering speed. Maxxis® tires help provide excellent handling and control. At 20 inches in the rear and 21 inches in the front, they provide better ground clearance than the competition.
Large diameter, tapered handlebars reduce vibration and are
mounted on 4-way clamps for exceptional adjustability. The two sets of holes in the handlebar crown and the eccentric
clamps allow a rider to choose the standard setting, 10mm or
20mm forward, or 10mm back.
Foot pegs are a generous 2.6 inches wide, something riders will
appreciate every time they want to get up on the pegs.
The frame is a combination of aluminum and steel for light
weight. The frame member under the engine is steel, used for
its combination of strength and low profile. This allows the engine to sit lower overall for excellent mass
centralization for unmatched handling. The aluminum frame is
bolted together, rather than welded, for maximum durability.
The front frame is as narrow as possible at the A-arm mounting points. This increases the A-arm length and reduces changes in camber as the suspension travels through its
full range of motion.
The front KYB® shocks are longer for increased stroke with superb bump absorption and excellent anti-bottoming characteristics, and they have Kashima™ coating for smooth operation. 9.8 inches of wheel travel means this racer is up to even the most challenging tracks.
The rear swingarm is crafted of strong, gravity-fed aluminum, and is matched to a fully adjustable 46mm KYB® piggyback shock for excellent handling. Rear wheel travel is 11.0 inches for comfort even on tough terrain.
The throttle lever requires low effort - less fatigue during long motos.
The discrete panel on the fender in front of the rider gives vital indicators about low fuel, coolant temperature, check engine, and neutral gear via an LED display.