- liquid-cooled DOHC 4-stroke; 4 titanium valves
- Constant-mesh 5-speed; multiplate wet clutch
- Yamaha Fuel Injection (YFI), Keihin® 44mm
- 449 cc
After the radical makeover received in 2010 the Yamaha YZ450F continued to receive small upgrades which help it remain on the same line with its rivals. The year 2012 brings a series of small upgrades as well. The most significant modifications were made to improve the ride, smoothen the gearbox and to give the engine a better response.
To help the bike absorb bumps easier, Yamaha gave it a new set of valves which help the suspension to deal easier with the difficult parts of the track thus transferring fewer vibrations to the saddle.
The engine’s modifications were kept to minimum and the unit received a more rigid shift fork to improve the transition between second and third gears. There were also made a few tweaks to make the throttle smoother and to increase its response in the low-mid range.
The engine is mounted on an aluminum double “S” bend Bilateral Beam frame which is perfectly suited for off road driving.
Hit the jump for more information on the Yamaha YZ450F
- YZ450F’s still revolutionary design advancements include its rearward-slanted cylinder that achieves unmatched mass centralization, concentrating inertial mass toward the center of the machine. This bold design swaps traditional intake and exhaust positions, putting the lightweight airbox and throttle body out front. This contributes to mass centralization for nimble handling while also achieving a straight intake tract for superb combustion efficiency that delivers more power.
- The cylinder is offset so the connecting rod is vertical at the moment of greatest combustion force, minimizing piston friction against the cylinder wall that could rob power. That means quicker response.
- The 4-titanium valve cylinder head is matched to a newly recalibrated fuel injection system that provides superb low-to-mid-rpm power feeling. Instantly adapts to changing air/fuel mixtures depending on altitude and temperature, for an engine that delivers no matter what conditions.
- The aluminum double “S” bend Bilateral Beam frame provides a superb rigidity balance and, with new front and rear suspension settings, provides unmatched lightweight handling and cornering. Combined with the mass centralization provided by the engine, YZ450F for 2013 is a formidable, well-tuned package.
- 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.
- The rearward-slanted engine allows for straight intake and exhaust ports, creating the most direct path for airflow 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.
- Fuel injection settings (mapping for injection and advance) offer smooth, controllable engine response in the low-to-mid-rpm range.
- 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.
- The big 97.0mm bore and short 60.8mm stroke, along with a high 12.5:1 compression ratio, create a combustion chamber that delivers really impressive power.
- The air filter case is up front, helping to keep dirt and dust kicked up from the rear tire 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-rpm torque characteristics, while the longer 94 dB muffler meets the latest noise standards.
Chassis and Suspension
- The aluminum double “S” bend Bilateral Beam frame is crafted from a carefully chosen combination of forged and extruded aluminum, 16 components in all, for the right rigidity balance and light weight. A very symmetrical chassis design promotes nimble handling, letting riders enter and exit corners as quickly as possible to put the competition behind them.
- Skid plate is constructed from tough polypropylene for great protection and low weight. The swingarm and rear shock are designed, with the shock mounted along the central axis of the frame, taking advantage of the space not needed for a traditionally configured engine’s airbox. This optimized combination delivers exceptionally linear performance for excellent bump absorption and awesome cornering ability.
- The KYB® Speed Sensitive front fork has excellent feel and shock absorption. KYB® rear shock includes a large capacity piggyback reservoir and 50mm piston for consistent damping control.
- Front and rear suspension settings and valving deliver exceptionally smooth suspension performance.
- Dunlop® Geomax® MX51 tires provide great all-round traction.
- Fuel tank is positioned underneath the seat, contributing to the centralized mass. The seat is long and flat to allow free rider movement, and has new seat foam material for an excellent cushion feel.
- The triple clamps have 22mm offset for unequalled cornering performance. The tapered aluminum handlebars are 4-way adjustable to accommodate a wide range of riders.
- The front and rear fenders, along with the number plate, side cover and front fork protector have been designed for an aggressive look. The bike’s minimalistic design accentuates its handling character. A minimum of plastic means the lightweight aluminum frame can be exposed for an enhanced performance look.
- Seat foam material has an excellent cushion feel.
- Both color options feature rich-looking black rims and a gold-color drive chain.
- Fuel pump is small and lightweight, as is the compact transistor ignition unit.
- Riders have a choice of two color options: Team Yamaha Blue/ White or White/Red. Clutch and transmission components are designed to give the rider positive and precise shifting feel.
|Engine Type||449cc liquid-cooled DOHC 4-stroke; 4 titanium valves|
|Bore x Stroke||97.0 x 60.8mm|
|Fuel Delivery||Yamaha Fuel Injection (YFI), Keihin® 44mm|
|Transmission||Constant-mesh 5-speed; multiplate wet clutch|
|Final Drive||Chain Drive|
|Suspension / Front||KYB® Speed-Sensitive System, inverted fork: fully adjustable, 12.2-in travel|
|Suspension / Rear||KYB® Fully adjustable single shock; 12.4-in travel|
|Brakes / Front||Hydraulic single disc brake, 250mm|
|Brakes / Rear||Hydraulic single disc brake, 245mm|
|Tires / Front||80/100-21 Dunlop® Geomax® MX51|
|Tires / Rear||120/80-19 Dunlop® Geomax® MX51|
|Seat Height||39.4 in|
|Ground Clearance||15.2 in|
|Fuel Capacity||1.6 gal|
|Wet Weight***||245 lb|
|Warranty||30 Day (Limited Factory Warranty)|