Bikes 19 Sep 2014

Tested: 2015 Yamaha YZ250F

MotoOnline.com.au rides and reviews the 2015 Yamaha YZ250F.

The new generation Yamaha YZ250F released for 2014 has proven itself both domestically and internationally as a force to be reckoned with in the quarter-litre class.

Its unique reverse engine design and mass centralised chassis layout create a very impressive platform in stock trim. In factory trim? The bike is clearly a standout; Luke Clout proved that aboard his Serco Yamaha YZ250F with the MX2 MX Nationals title this year.

Clout’s teammate Jay Wilson also rode his YZ250F to fourth overall in the MX2 championship while GYTR Yamaha’s Jed Beaton narrowly missed out on the MXD title aboard his YZ250F due to an unfortunate late-season leg injury.

To top off a stellar year for Yamaha’s 250 four-stroke, Jeremy Martin wrapped up Yamaha’s first 250 Class Pro Motocross Championship in the US with the YZ250F. With all of this success, it was obvious we were in for a treat hopping aboard the 2015 model at Queensland Moto Park for the official Australian launch.

As the 2014 model was already so strong and successful, Yamaha didn’t go ahead and fix something that wasn’t broken – they massaged it ever so slightly. The KYB 48mm speed sensitive fork remains for 2015 featuring stiffer fork springs, new valving and a new fork outer tube to improve performance in the mid-to-end stroke and aid fork bottoming resistance.

Image: 64MX Photography.

Image: 64MX Photography.

The rear suspension also features settings optimised for ideal damping characteristics to match the overall chassis dimensions and fork setting updates. A large-diameter 22mm front axle and top triple clamp also increase rigidity for excellent handling and front-end feel.

The overall balance of the 2015 YZ250F is very central and provides a stable feel at higher speeds, while still being able to turn on a dime. These stable, yet agile characteristics are a key factor in the success of the new generation YZ250F, it covers all areas very well.

The 2015 YZ250F shares the same bilateral beam frame design as it’s older brother, the YZ450F. Although the 250F doesn’t feature a steel engine mount system like the 450 for 2015, it’s not a worry because it didn’t need that extra flex and front end feel that the 450 benefits from.

This chassis design focuses solely on mass centralisation and is something that Yamaha has really nailed. The way they have designed this bike is super impressive, and the best part is that it actually works the way they claim that it will.

A liquid-cooled, DOHC four-valve, fuel-injected engine with the same forward-positioned straight intake, rear-inclined cylinder and rear-positioned exhaust layout as the YZ450F is housed within the aluminium frame.

The engine, with its straight and symmetrical intake and exhaust ports and compact, high-compression combustion chamber, delivers outstanding power and torque right out of the box. Our guest test rider for the day, Dylan Wills, who typically rides a 250 two-stroke was very impressed with the engine package in stock form.

The adjustable fuel injection system uses a 44mm throttle body fed by a high-pressure battery-less electric fuel pump. This ensures optimum fuel atomisation and air/fuel calibration for excellent rideability in a wide range of riding conditions.

The system controls the volume of fuel injected and the ignition timing based on engine rpm and throttle opening, providing hesitation-free response and controllability. You can lug this bike around in a taller gear, or rev it to the moon, either way, it delivers smooth and strong power at all times.

The specs for the intake/exhaust ports, cam profiles, ECU, carburised crank, optimised balance ratios for the crank web, transmission, clutch design and other features, all work together to create the YZ250F’s outstanding engine character with power output in the high-rpm range.

A compact wet sump lubrication system with piston cooler spray jet maintains excellent engine durability and eliminates the need for an oil tank, which lowers engine weight. This creates a more compact engine that contributes to mass centralization and impressive handling.

Image: Plan V.

Image: Plan V.

Ergonomically the 2015 Yamaha YZ250F is on point and it’s unique design actually improves the ergos quite a bit. By moving the fuel tank below the seat and placing the airbox where the tank would usually be located, this allows for seemless movement from the rear of the bike to the very front – no fuel cap!

That air filter design has also been improved for 2015 with quarter-turn clips now featured for quick and easy access. No longer will you need any tools to check or change your air filter, big plus right there.

For 2015 the Yamaha YZ250F also features black Excel rims from the factory, this addition just gives the bike that mean and clean look we all want. It also saves you money if you’re one of those people who needs to look fast in the pits with fresh black wheels – you’ve got them already for 2015.

Adding to the looks of the bike are in-mold technology graphics, a method in which the graphics are molded into the radiator shrouds for improved decal durability and reduced scratches. And don’t worry, if you want to use aftermarket graphics, just stick them right over the top.

Buyers also have a choice of two color options in 2015, Team Yamaha Blue/White or the White/Red colourway, take your pick. If you’re in the market for a new 2015 250 four-stroke, it’s highly recommended that you take a look at the YZ250F which retails for $10,999 at your local dealer now.

Click here for detailed specifications

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