2012 Yamaha WR450F Enduro
New fuel injection system and
compact new chassis
Yamaha’s WR450F is recognised as being one
of the toughest and most reliable bikes in the enduro
world, claiming prices in the AIM Cross-Countries
World Championship, the Enduro World Championship
and of course the gruelling Dakar Rally. The current
model accounts for around 30% of all sales in the
450cc enduro market in Europe, North America and Australia.
This strong demand for the model underlines its enduring
popularity with enduro and trail riders all over the
world, and for 2012 the company will introduce a new
WR450F which is designed to keep the Yamaha name at
the forefront of the highly competitive E2 class.
Featuring an all-new tuneable fuel injection system,
the proven WR-F’s 450cc 4-stroke liquid-cooled
5-valve engine now delivers even more responsive and
adaptable performance to suit the wide range of conditions
experienced by enduro riders. As well as the new fuel-injected
engine, the 2012 WR450F runs with a compact new bilateral
aluminium beam frame which brings new levels of agility
to the 450 class. Manufactured from a combination
of forged, extruded and panel aluminium components,
this innovative new lightweight frame has been constructed
to 250-class dimensions, giving the quick-turning
WR450F a real advantage in the tight corners and twisty
woodland riding found in the typical enduro.
In addition to the uprated engine and new frame,
the 2012 WR450F also features new slimline bodywork
which underlines its 250-class dimensions - and with
new black Excel rims, Pro-Taper bars and a new headlight
cowl, this front-running E2 enduro machine comes with
winning looks to back up its winning performance.
New WR450F from Yamaha. The Real Enduro Racer.
Engine
New tuneable fuel injection system
The WR450F’s ultra-reliable liquid-cooled,
4-stroke, DOHC, single-cylinder, 5-valve 449cc engine
has become a real favourite with enduro and trail
riders looking for a wide band of strong and controllable
power – and the demand for this rugged and reliable
racer looks set to grow significantly now that it
is equipped with an advanced new fuel injection system.
By the very nature of the sport – in which
riders can typically cover hundreds of kilometres
or more each day – enduro bikes can often experience
major changes in altitude, air temperature and weather
conditions in a matter of hours. In order to ensure
efficient and effective engine running in a constantly
changing environment, the compact new fuel injection
system that is fitted to the 2012 WR450F is programmed
to continuously adjust its settings to match the prevailing
conditions.
A series of miniature sensors transmit information
on throttle position, intake pressure, intake temperature,
air pressure, crank rpm and coolant temperature to
the compact ECU, and this calculates and activates
both the optimum fuel injection volume and ignition
advance required to ensure high levels of combustion
efficiency for enhanced engine performance. And to
keep weight to a minimum, the 2012 WR450F uses the
same lightweight and compact fuel pump already featured
on our YZ-F models.
The addition of a new fuel injection system for 2012
not only ensures that the WR450F delivers even more
stable and responsive performance in a wide range
of operating conditions – the wide powerband
and excellent driveability of the uprated engine also
enables the rider to concentrate fully on the terrain
ahead, while the seamless engine performance helps
to reduce rider fatigue.
Competition kit parts
The new 2012 WR450F will be supplied by Authorised
Yamaha Dealers with WVTA specifications. A separate
Competition Kit for the 2012 WR450F is also available
for those riders who will be using the machine in
closed course enduros. The kit comprises a number
of race-specification performance parts including
an exhaust pipe, silencer, tail pipe, 13/50 sprocket
set and other items.
New racing exhaust system with resonator
The exhaust pipe included in the Competition Kit features
a built-in resonator which has been designed to optimize
the pulse effect of the intake/exhaust system. This
resonator system is already used successfully on Yamaha’s
MXGP-winning factory YZ-F models, and it contributes
to improved power output in the important low to mid-speed
range, which is particularly significant on an enduro
bike where races are often won or lost in the slower
tight and twisty conditions.
Easy-to-use Power Tuner
Following its success on our YZ450F motocross bike,
Yamaha will offer WR450F riders the option to purchase
a Power Tuner. This pocket-sized device has been designed
to allow riders to fine-tune the performance of WR450Fs
fitted with the Competition Parts kit, and it opens
up a whole new world of possibilities.
The WR450F is supplied by the factory with a standard
fuel injection map which is designed to give the machine
strong performance in a wide range of riding conditions.
However, on bikes fitted with Yamaha’s Competition
kit parts, riders can use the Power Tuner to make
adjustments to the fuel injection volume and ignition
timing to suit specific track conditions and also
to complement their riding style.
The Power Tuner is compact and simple to use, and
does not require a PC to activate any changes to the
map. All the rider has to do is simply connect the
Power Tuner to the coupler located on the bike and
key in the desired performance characteristics. The
bike’s ECU runs with two 3-dimensional programmes
which feature a fuel injection map and an ignition
timing map, and these maps include engine rpm and
throttle opening as parameters. The Power Tuner allows
riders to independently adjust fuel injection volume
at 9 different setting points, and likewise the ignition
timing can also be adjusted at 9 different setting
points.
Using the Power Tuner, a rider can select any one
of 15 different values at each of the 9 setting points
on the fuel injection map, with each ‘step’
representing a 3% change in fuel injection volume,
giving a range from -21% through to + 21% from the
standard factory setting. Similarly, on the ignition
advance map, Power Tuner users can select any one
of 14 steps, with each step representing a 1º
change in ignition advance, giving a total adjustment
from -9º to +4º from the standard factory
setting.
By experimenting with various fuel and ignition settings,
riders are able to create their own customized maps
that best suit their individual style and the prevailing
riding conditions. After evaluating and noting which
maps work best in specific situations – for
example map 1 for sand, map 2 for mud, map 3 for rock
and so on – riders can save a total of 9 maps
on their Power Tuner and then reprogramme their WR450F
on the morning of the enduro with the specific map
that will suit that day’s riding and surface
conditions. WR450F owners can also benefit from other
riders’ data by comparing each others’
maps and sharing them, allowing more experienced riders
to pass on their set-up knowledge to newer riders.
Another advantage is that the Power Tuner also has
a monitor function which allows the user to look at
data from the various different sensors, as well as
see engine running time. There is also a malfunction
self-diagnosis function which gives greater ease of
maintenance.
Vibration-resistant radiator design
For outstanding heat dissipation qualities together
with increased strength the WR450F is equipped with
a new radiator design which ensures stable running
even in tricky low-speed going where airflow is reduced.
First used on the latest-generation YZ250F, this vibration-resistant
radiator features a thicker core, and for added durability
the mount is changed from a two-point to a three-point
system.
High-capacity ACM and new condenser
To match the demands of the new fuel injection system
the latest WR450F is fitted with a high-capacity three-phase
AC magneto generator – and for reliable kick
starts in the event of a problem with the battery
function, a condenser has been added to the bike’s
electrics.
Engine Technical Highlights
- Liquid-cooled, 4-stroke, DOHC, single-cylinder,
5-valve, 449cc electric-start engine
- New Fuel Injection system
- Compact YZ-style fuel pump
- Separate Yamaha Competition Kit with resonator
exhaust system, 13/50 sprocket set and other parts
- Optional Yamaha Power Tuner for customized fuel
injection volume and ignition timing settings
- Linear power delivery with stable performance
in differing conditions
- Titanium valves
- 12.3:1 compression ratio
- Balancer mechanism
- High-capacity three-phase AC magneto generator
- New condenser for reliable kick starts
- Vibration-resistant radiators with new 3-point
mounting
- Enduro-specific camshaft profile
- Dry-sump lubrication system with inbuilt crankcase
1.2 litre oil tank
- Enduro-specific 5-speed transmission
Chassis
Compact new aluminium bilateral beam frame
The new 2012 WR450F has been designed to offer new
levels of handling performance for a 450, and for
quicker cornering together with easier direction changes
and a feeling of lightness, the bike runs with an
all-new frame design which is one of the most compact
designs in the class.
Featuring twin aluminium spars running from the headstock
right down to the engine cradle, this new bilateral
beam frame has been developed from the latest YZ250F
design, and it offers a number of important advantages
over the previous design.
The bilateral design has enabled our designers to
relocate items such as the fuel tank and radiators
in order to achieve a greater centralisation of mass
for quicker and easier direction changes when entering
tight corners. As every competition rider knows, races
are won or lost in the turns, and over the course
of a day’s racing, a fraction of a second saved
in every corner can add up to a massive advantage
by the end of the event.
Unlike some conventional frames, the new Yamaha bilateral
design is manufactured from a unique combination of
forged, extruded and panel aluminium parts which are
welded together to create a unit offering an idealised
balance of rigidity. Not only is this frame extremely
compact – in fact it feels more like a 250 than
a 450 – but its finely balanced lateral and
torsional rigidity values gives excellent rider feedback,
allowing the rider to feel what the bike is doing
and respond accordingly.
Enduro-specific 250-class dimensions
When we set out to develop the new WR450F, our main
priority in the chassis department was to create a
machine with a feeling of lightness and agility which
would deliver class-leading cornering performance.
Any enduro racer who gets on the new WR450F is sure
to be impressed with the compact feel and slim dimensions
of this new-generation race bike.
Developed from the latest slimline YZ250F design,
the 2012 WR450F frame features a number of enduro-specific
changes to the shape and thickness of various components,
as well as redesigned engine and subframe mountings,
and the use of a different alloy for the subframe.
Running with a compact 1,475mm wheelbase –
25mm shorter than the existing model – as well
as a 27 degree caster and 115mm trail, the new WR450F
gives a feeling of lightness and agility together
with excellent front wheel tracking and rear wheel
traction. The result is a new kind of 450 whose lightweight
aluminium chassis feels and behaves more like a 250
in the twists and turns, and once out in the open
the rider can exploit the wide powerband and explosive
acceleration of the new fuel injected 450cc 5-valve
engine.
Enduro-specific suspension settings
As well as its all-new bilateral beam frame, the WR450F
is also equipped with a new air/liquid separation
type front suspension system which is based on the
design used on Yamaha’s MXGP winning YZ-F models.
Running with lightweight flex-resistant 48mm tubes,
the upside-down front forks benefit from enduro-specific
damping and spring rate settings for smooth and responsive
low speed characteristics in tight turns, combined
with good high speed stability.
The link-type monocross rear suspension system also
runs with specific spring and damping settings which
have been developed to suit the needs of enduro riders,
with a softer initial stroke for smoother low speed
handling in tight corners. And with full adjustability
at the front and rear, the WR450F chassis can be fine-tuned
to suit individual riding styles and different terrain.
New-design slimline plastic resin 7.2 litre
fuel tank
The new bilateral aluminium frame carries the new
plastic resin fuel tank between its beams which helps
to increase mass centralisation for more agile turning.
This specially designed tank offers a capacity of
7.2 litres (1 litre more than the YZ450F), giving
a good range for competition and trail riders. And
for added convenience a fuel warning lamp is fitted
to the instrument console, and this alerts the rider
when the level reaches 2 litres.
Slimline bodywork
To underline the compact dimensions of its 250-class
frame, the new WR450F is equipped with all-new bodywork
which gives the bike a sharp new profile to match
its high specification. Lightweight air scoops direct
cool air into the new vibration-resistant radiators
and offer plenty of knee grip when standing –
and newly-designed side covers accentuate the bike’s
feeling of lightness. And with an all-new headlight
cowl and an LED rear light, the 2012 WR450F’s
cutting-edge styling perfectly complements its sophisticated
engine and chassis specification.
High-grip seat
To accommodate the long periods that enduro riders
can spend in the saddle each day, the new WR450F is
equipped with a specially-developed seat which is
designed to give greater comfort and reduced fatigue.
The tank and seat profile are designed to allow smoother
body weight shifting, and the seat features a high-grip
cover for improved rider control in wet conditions.
For improved useability the new seat height is reduced
to 960mm, which is 30mm lower than on the existing
model.
High specification components
For 2012 the WR450F comes fully-equipped with black
Excel rims which give the bike an impressive new ‘factory
racer’ look, and Pro Taper handlebars are also
fitted as standard. These high quality components
not only underline our designers’ close attention
to detail, but they also reinforce the pride of ownership
felt by owners of this outstanding new enduro bike.
Chassis Technical Highlights
- New all-aluminium bilateral beam frame
- Manufactured from a combination of forged, extruded
and panel aluminium components
- Centralisation of mass for easy turning
- Idealised balance of strength and rigidity to
suit enduro conditions
- Compact and slim design for light handling character
- 1,475mm wheelbase, 25mm shorter than existing
model
- Enduro-specific 250-class dimensions
- YZ-F type front suspension with air-liquid separation
- Optimized enduro-specific rear suspension settings
- Enduro-specific high-grip seat
- Lower 960mm seat height
- New-design slimline plastic resin 7.2 litre fuel
tank
- Black Excel rims
- Fuel level warning light shows when level reaches
2 litres
- New-look headlight cowl
- Newly-designed side covers
- Wave-shaped front and rear discs
- Wide footrests for optimal grip and comfort
- Pro-Taper handlebars
- Lightweight aluminium sidestand
- Tough one-piece resin engine guard with 335mm
ground clearance
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