In ATV motocross,
great power output doesn’t mean
much without superior handling. YFZ450R
delivers! Nearly three inches wider
overall than the YFZ450, the stance
of this new 450R is motocross-ready.
The weldless frame is designed of
lightweight aluminum, with a tension-steel
bottom frame that lets the engine
sit lower for excellent mass centralization.
Suspension components have more travel
carefully chosen for best performance,
and the front shock bodies feature
Kashima coating for even smoother
operation.
Fatigue can sometimes
be a racer’s worst competition.
That’s why the YFZ450R’s
designers made this ATV so comfortable.
It’s much roomier, with plenty
of room to hang off in the corners,
and the seat is padded just right
to be more comfortable regardless
of riding position. Handlebars are
4-position adjustable, too, so every
rider can choose the best position,
and the throttle has been designed
for all day comfort. What’s
more, the engine balancer has been
revised to even further reduce vibration.
This 449cc engine
uses the cylinder head and cylinder
from the championship-winning YZ450
for awesome power output. That means
titanium five-valve cylinder head
technology, with a camshaft designed
just for this machine to deliver abundant
low to midrange torque for performance
where you can really use it to take
the lead – while still maintaining
a super strong top end to let you
pull away from the pack.
The YFZ450R adopts
fuel injection for precise fuel delivery.
With 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.
This ATV is designed
to make race prep easy. Body panels
come off easily for service; there’s
no need to remove the battery or other
components to get the fenders off.
The aluminum frame is bolted together,
rather than welded, for maximum durability.
And the oil tank is integrated with
the crankcase so it’s easier
to service the engine.
Yamaha
YFZ450 ATV Engine
The fuel-injected
449cc engine uses the cylinder head
and cylinder from the YZ450 for superb
power characteristics. Power delivery
is smooth and strong off the line
with lots of low and mid range where
you need it. As rpm climbs you’ll
find the same top end punch that has
made the YFZ450 such a fierce competitor
and class leader.
The new crankcase
holds the newly designed crankshaft
that’s ready to handle the increased
torque output, as well as the counterbalancer
that has an increased ratio for superior
vibration control. The crankcase also
houses the oil tank, which helps to
centralize mass for unmatched handling
and makes maintenance easier.
Camshafts are all
new for this model, and are designed
to maximize the torque available in
the low and mid ranges.
Fuel injection uses
a 12-hole injector that provides exceptional
atomization of the fuel for maximum
combustion efficiency and power delivery.
The system also uses a big, 42mm Mikuni®
throttle body and includes ISC (Idle
Speed Control) for easy, reliable
start-up and warming.
Yamaha
YFZ450R Sport ATV Top and Bottom Views
Yamaha
YFZ450 ATV Chassis/Suspension
The chassis is very
spacious, allowing room for an aggressive
racer to move around during the moto,
and the ATV’s body panels that
the rider contacts during operation
are of a special, softer plastic material
for greater comfort. And the seat
is narrow in the front, yet wide and
padded in the rear to provide a more
comfortable ride, even when hanging
off on the side of the seat in a turn.
Wheels are set motocross-spec
wide, near the maximum allowable 50
inches, for great cornering ability.
The newly designed Dunlop® tires
are grippy with a great pattern for
cornering, and at 20 inches in the
rear and 21 inches in the front, provide
much better ground clearance than
the competition. That makes the YFZ450R
fun to ride off-road, too.
ProTaper® handlebars
are mounted on 4-way clamps for exceptional
adjustability. There are two sets
of holes in the handlebar crown, and
eccentric clamps so the rider can
choose the standard setting, 10mm
or 20mm forward, or 10mm back.
Foot pegs are huge
65mm, something riders will appreciate
every time they want to get up on
the pegs, with good kick-up on the
ends for solid footing.
The all-new frame
is aluminum for lightweight, except
for the frame member under the engine.
Here tensioned steel is used to allow
the designers to position the engine
lower overall for excellent mass centralization
for unmatched handling. The frame
is bolted together, rather than welded,
for maxium durability.
The front frame is
noticeably narrow at the A-arm mounting
points. This dramatically reduces
changes in camber as the long A-arms
travel through their full range of
motion. The front 44mm KYB shocks
have Kashima coating for smooth operation
with superb bump absorption and excellent
anti-bottoming characteristics. The
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 it’s matched to
a fully adjustable 46mm KYB piggyback
shock absorber for excellent handling.
Rear wheel travel is 11.0 inches for
comfort even on tough terrain.
For excellent stopping
ability, YFZ450R features dual front
hydraulic disc brakes and a trick
looking, lightweight wave-type rear
rotor.
Additional
Features
The new throttle
lever requires less effort, and it’s
very comfortable to use. That means
less fatigue during all-day riding.
The instrumentation
is all business. 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 a straightforward
LED display.
