It’s been a year since Yamaha revolutionised the MX world with the
introduction of the reverse-fed YZ450F. And it’s safe to say that the new
bike has hit the ground running.
With James Stewart out injured, it was
left to Aussie rider Jay Marmont to show how capable the YZ450F is in the
white heat of competition. Not forgetting Canadian rider Dusty Klatt
who replicated Jay’s feat by scooping a third national title in a row for
the YZ450F.
It’s a results business and such feats confirm the agility of
the bilateral beam frame, the linear power delivery offered by the sweet
fuel injection system and awesome punch from the high torque four-valve
motor.
Taking mass centralisation in a different direction by fitting a rearward
facing and backward tilted cylinder has paid off. And one of the major
advantages of the machine is the optional plug-in Power Tuner that allows
riders to go from mild to wild in seconds.
So whether you require the full power Marmont Map or a somewhat
easier-to-hang-onto Clubman Curve, the YZ450F is all things to all riders.
One year on but still leading the way.
Features:
YZ450F’s revolutionary rearward-slanted cylinder achieves unmatched mass centralisation, concentrating inertial mass toward the centre of the machine. This bold design also swaps traditional intake and exhaust positions, putting the lightweight airbox and throttle body out front. This contributes to mass centralisation for nimble handling while also achieving a straight intake tract for superb combustion effi ciency that delivers more power.
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The cylinder is offset so the connecting rod is vertical at the moment of greatest combustion force, minimising piston friction against the cylinder wall. That means quicker response.
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The 4-titanium valve cylinder head is matched to a fuel injection system developed specifically for the YZ450F. Instantly adapts to changing air/fuel mixtures depending on altitude and temperature, for an engine that delivers no matter what conditions.
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The aluminium Bilateral Beam frame provides a superb rigidity balance that complements the engine for unmatched lightweight handling and cornering.
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New for 2011 is a longer clutch actuation arm for a featherlight clutch operation.
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Accessory GYTR Power Tuner lets bike tuners adjust air/fuel mixture and ignition timing maps to match engine performance characteristics to the rider and track conditions.
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| The rearward-slanted engine allowed engineers to design straight intake and exhaust ports, creating the most direct path for air flow into the fuel-injected engine for incredible performance. |
| The YZ450F uses a battery-less fuel injection system with a 12-hole injector for superb fuel atomization. The 44mm Keihin throttle body is designed for easy starting, with an integrated cold start and idle speed adjustment knob. Yamaha FI provides optimal air/fuel mixtures in all altitudes and wide range of temperatures for outstanding throttle response. |
| 14 volt / 110W high output generator powers the battery less fuel injection system. |
| 4-titanium valve cylinder head with a pent-roof design combustion chamber provides excellent combustion efficiency and unequalled power output. |
| Intake and exhaust camshaft profile changes to increase valve working angle and valve lift for most excellent performance at all rpm. |
| 97.0mm bore and short 60.8mm stroke, along with a higher 12.5:1 compression ratio, create a combustion chamber that delivers really impressive power. |
| Front located air fi lter keeps dirt and dust kicked up from the rear tyre away from the intake system. |
| Tornado-style exhaust header with resonator efficiently scavenges exhaust gasses and helps the engine achieve its exceptional low-to-mid range torque characteristics, while the muffler comfortably meets the latest noise standards without a sacrifice of power. |
| Aluminium Bilateral Beam frame is crafted from a carefully chosen combination of forged and extruded aluminium, 16 components in all, for the right rigidity balance and light weight. |
| The skid plate is constructed from tough polypropylene for exceptional protection and low weight. |
| Rear shock is mounted along the central axis of the frame, taking advantage of the space no longer needed for the front-mounted airbox. This optimised combination delivers exceptionally linear performance for excellent bump absorption and awesome cornering ability. |
| KYB Speed Sensitive front fork has long stroke for excellent feel and shock absorption. |
| KYB rear shock with large capacity piggy back reservoir and 50mm piston for more consistent damping control. |
| Fuel tank is positioned underneath the seat, contributing to the centralised mass. The seat is long and flat to allow for free rider movement. |
| Rear sprocket shape has a trick appearance and is light weight. |
Specifications:
Engine
| Engine Type |
Liquid-cooled, 4-stroke, DOHC, 4-valve |
| Displacement |
449.7 cc |
| Bore x Stroke |
97.0 x 60.8 mm |
| Compression Ratio |
12.5 : 1 |
| Lubrication System |
Dry sump |
| Fuel Management |
EFI |
| Ignition |
TCI |
| Starter System |
Kick |
| Fuel Tank Capacity |
6.0 L |
| Oil Capacity |
1.2 L |
| Final Transmission |
Chain |
| Transmission |
5-speed |
Dimensions
| Length |
2194 mm |
| Width |
825 mm |
| Height |
1311 mm |
| Seat Height |
998 mm |
| Wheelbase |
1487 mm |
| Ground Clearance |
383 mm |
| Wet Weight |
111.5 kg with 6.0 litres of fuel |
Chassis
| Frame Type |
Bilateral beam frame |
| Suspension Front |
Telescopic fork, 330mm travel |
| Suspension Rear |
Swingarm (link suspension), 312mm travel |
| Brakes Front |
Single disc |
| Brakes Rear |
Single disc |
| Tyres Front |
80/100-21 51M |
| Tyres Rear |
120/80-19 63M |
*Special Edition (White): $13,899.00
