A number of adjectives could be used to describe the new 2014 Yamaha YZ -F range but the truth is that the YZ250F and YZ450F speak volumes simply on their own. Yamaha’s latest bold and advanced stride towards off-road excellence has again taken these motorcycles into fresh territory. Take a look: forward-thinking, forward-riding…

The new generation of YZ-F draws the new motorcycles closer together than ever before. The YZ450F and YZ250F share the same platform and gamut of technology. Attributes that distance the YZ-F family from the competition:

• advanced concept behind the rear-slanting engine layout
• new snaking exhaust pipe flow from the back of the cylinder head

The YZ450F has been a staple forerunner of this design for four years.  This has been the benchmark in terms of performance, feedback and tractability. In 2014 and the fuel injected YZ250F now draws on the matching base and potential.

Ultimate Power, Character and Behaviour.

At the core of the 2014 YZ-Fs is the same beating heart. The shared engine principles behind the deliverance of the best and most usable spread of power and output yet is a major calling card of these new motorcycles. Both motors are fuel injected to bring the range bang up to date with the latest propulsive engineering available on the market. For the YZ-F pair, this means excellent power characteristics, more response and grunt across the band.

The 2014 YZ250F proves that time, dedication and passion are forceful elements in the creation of an agile, reactive and rapid racing weapon. The engine might share ingredients of its ‘big brother’ but the completely fresh configuration also has special components of its own:

• a new cylinder head,
• piston,
• larger intake and exhaust ports,
•  valve mechanisms and
• ignition timing with a lighter crankcase; that is just one of several features that slims weight.

The quarter-litre is a resolute statement of intent by Yamaha for 21 century off-road riding and racing but the YZ450F has had more than just a makeover. The very essence of the YZ450F lies in the attention-grabbing 450cc fuel-injected, liquid-cooled, 4-stroke, 4-valve, DOHC, rearward-slanting single-cylinder engine. For 2014 this powerplant now boasts a controllable and greater – more usable – character. The larger valves form a part in the revaluated performance while a new ECU and gear rations mean plenty of easy-to-play-with torque in the first gears with a strong push through the powerband from the third gear up. Overhauled intake and exhaust ports, cam profiles and crank ratios make the YZ450F is most tractable and invigorating ride yet in the short history of the bike.

For both YZs the ‘MX Power Tuner’ accessory allows swift customisation of the motor’s settings for preference or different terrain making the 2014 Yamaha YZ s line-up not only the finest motocross offering Yamaha have yet to produce but also the most rewarding and personal.

2014 Yamaha YZ: Ultimate Cornering Control

To house the sensational engines and force the components of the bikes into a melting pot of centralised mass comes a revised 250 class dimensioned chassis that blends renewed levels of rigidity, balance and shock-absorbing elements for a sturdy cornering tool. A hydro-formed bilateral beam frame with ten different types of forged, cast and extruded aluminium parts assist the feeling of precision when in motion.

If the engine is the superlative heart of the new 2014 Yamaha YZ s then the chassis is the wholly impressive skeleton that pushes this particular ‘athlete’ onwards and keeps it on the steady path. A new thinner and trimmed radiator and shorter sub-frame and several lighter components contribute to the lighter feel and weight saving. The sensation of lightness has been achieved with reduced crankcase dimensions, overhauled and simplified lubrication systems with a wet sump and a compact fuel pump.

On the suspension proven upside-down forks with air-liquid separation type shock absorbers use new inner tube springs and effectively work with a wider 22mm diameter of the front wheel axle. Increased rigidity in the handlebar crown augments the YZ250F/YZ450F’s agility and ability to grip the dirt while a new rear shock spring provides a gentle and reassuring damping effect.

Over the years the YZ250F has become renowned for turning on a dime; this model will also propel you out of a corner before you know it. The motorcycle breathes an image of the ultimate competition. Look towards the YZ450F and you’ll see the same, but, fascinatingly, the growling motor is able to call upon exactly the same chassis and framework as its brother.

Ultimate Feedback and Excitement

Getting ‘lower’, ‘closer’ and more ‘central’ with the mass-composition of off-road motorcycles to improve grip, feel and handling have presented interesting technical challenges to the engineering department in Iwata over the last decade. With the 2014 Yamaha YZ ‘double’ the aim of creating the crux of a bike that will not only bubble the adrenaline but also inspire confidence and assurance has reached a peak. The YZ250F and YZ450F benefit from mass centralisation aspects such as the snaking exhaust pipe layout and deeper location of the increased capacity fuel tank (bigger by over a litre), ideal central placement of the fuel injection components such as the engine ECU and a new wire harness. The innovative exhaust curvature – first introduced by the Monster Energy Yamaha Grand Prix team on their Factory machine – extends length and permits an excellent pulse effect and power development. This is because of the variance in the diameter of the pipe itself starting from the cylinder head all the way to the silencer. The spiralling form of the exhaust means the muffler can be shortened and pulled closer towards the middle of the bike; again assisting with mass-centralisation augmenting a stable and confidence inspiring experience.

The 250 boasts a new, stronger gear-shift system that works in impressive harmony with a smoother clutch. In combination with other elements of the new 2014 engine, these changes make a big contribution to the shift continuity between gears and depth in power output and build. A crucial facet of the 2014 engineering goal focuses on the reduction of horsepower loss and builds the effect of a feistier but smoother ride.

The sheer availability and versatility of the engine power on the YZ450F will again make the motorcycle a valuable asset from deep sand to the rapid and rutted mounds of motocross tracks. The clutch uses different compression springs and optimised plates and new specs are adopted for the drive axle, main axle, gear wheel and pinion gear. This offers smoother and surer shift action combined with better clutch feedback The adjusted ratios make the bike ‘punch’ in first and second gear and then the ‘take-off’ from third really propels the rider.

Glancing at the 2014 Yamaha YZ s will easily turn into a long stare. As a reaction to the refinement elsewhere, the styling and aesthetics present a striking new form.

The compact and sharp profile screams ‘race me’. It is here that the plastics and previously stated enhancements to the bike contribute towards the shape. The standout visual is the ‘disappearance’ of the fuel tank hub with the whole 7.5l unit buried into the machine but still facilitating easy access, particularly to the air filter for improved serviceability. The seat and rear fender have been overhauled and the air scoop is a prominent feature of the motorcycles’ leaner and meaner ‘face’ for 2014. New lines are evoked through the ‘in mould’ graphics; a deployed method inside Yamaha in which the graphic film is inserted into the injection mould before the part is cast so that graphics are morphed into the piece itself, giving it a translucent look and a surface that is more resistant to scratches and wear. The observer’s eyes are guided towards the centre of the bike where the heart and soul of this motocross project ultimately lies and where the best performance can be discovered.

2014 Yamaha YZ Colors

These are available in two colours:

• Racing Blue
• Sports White