Topping last season's all-conquering YFZ450 was always going to
be a challenge. The new 2009 YFZ450R successfully steps up to
Sports ATV pole position by moulding totally uncompromising
engineering into instant race-winning potential.
The YFZ450R story starts with a new, massively rigid but very
lightweight cast aluminium and steel hybrid chassis. Though the
footprint is wider and the suspension longer than the YFZ450's, the
YFZ450R is physically shorter overall than its predecessor, giving
it a more agile, nimble feel.
Sitting low in this chassis is a 449cc 5-valve DOHC
liquid-cooled engine with reshaped intake ports and fuel injection
controlled by a 32-bit ECU.
The engine's dry-sump design allows for a shallower crankcase,
lowering the centre of gravity still further for even sharper
handling. Pressure lubrication from a separate (small) drysump tank
inside the crankcase reduces weight and rules out oil starvation
under high G-forces.
The intake port design and valve timing have both been modified
for increased low and midrange power. A new exhaust boosts low and
midrange power, while a new five-speed gearbox with taller ratios
drives through an up-rated clutch. The result is an ATV packing
linear, muscular acceleration.
Increased wheel travel and longer suspension arms maximise the
YFZ450R's performance potential without compromising overall
balance, handling or agility. New tread-pattern tyres make turn-in
even sharper and a lightweight 220mm 'wave' disc reduces unsprung
weight. Ideal riding ergonomics are made possible by a four-setting
handlebar adjustment system, a new throttle lever, remodelled seat
and wider footrests.
Current Australian #1 plate holder Ryan Lancaster will upgrade
his all conquering YFZ450 to the new YFZ450R for 2009, competiition
watch out!
KEY FEATURES
In ATV motocross, great power output doesn't mean much without
superior handling.
YFZ450R delivers! 75mm wider overall than the YFZ450, the stance
of this new 450R is motocross-ready. The frame is designed of
lightweight aluminium, with a tension-steel bottom frame that lets
the engine sit lower for excellent mass centralisation. 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 fuel atomisation 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 aluminium 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.
ENGINE
Power deliver 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
centralise 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
atomisation 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 startup and
warming.
CHASSIS
Spacious ergonomics allow 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
1270mm, for great cornering ability.
The newly designed Dunlop front tyres have a superb combination
of the right compound, tyre profile, tread pattern, and
sidewall-totread- centre-stiffness ratio to provide outstanding
comfort, bump absorption, and precise cornering performance. The
rear Dunlop tyres also help the rider achieve a high level of
performance with superb feedback in turns and great grip on the
turn exit. At 20 inches rear and 21 inches front, the tyres also
provide much better ground clearance than the competition. That
makes the YFZ450R fun to ride off-road, too.
ProTaper handlebars are mounted on four-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 a huge 65mm wide, 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 aluminium for lightweight, except for the
frame member under the engine. Here tensioned steel is used for its
combination of strength and thinness. This allowed the designers to
sit the engine lower overall for excellent mass centralisation for
unmatched handling.
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 250mm
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 280mm 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.
OTHER
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.
For further information contact:
Sean Goldhawk, advertising and PR co-ordinator
Yamaha Motor Australia,
489-493 Victoria Street, Wetherill Park, NSW 2164
Office: (02) 9757 0068
Mob: 0438 423844
Fax: (02) 9757 1384
Website: www.yamaha-motor.com.au