The 2014 Yamaha YZ250F follows the lead of the larger YZ450F and uses a rearward slanting cylinder that is "reversed" compared to traditional designs, as well as an innovative circular exhaust system in which the header pipe winds its way around the cylinder body before turning to the rear of the bike. New ergonomics also help the rider during weight transfers.

Styling continues to evolve with more modern lines, a svelte body, and a new fuel tank that's mounted completely under the long seat. Let's not forget the premium Takasago EXCEL wheels.


Unique architecture
Using the latest engineering technologies available, the 2014 Yamaha YZ250F benefits from an injection system designed to withstand the stress of competition where multiple jumps are involved. While it shares plenty of components with its 450cc sibling, the YZ250F stands out with a lighter piston, larger intake and exhaust ports, a new valve train, and a lighter crankcase. It also improves from a dry-sump lubrication system to a wet-sump unit.

Yamaha engineers revised the gear ratios and upgraded the radiators. Fuel tank capacity has increased from 6.5 litres to 7.5 litres, and the bike's overall weight jumped from 103kg to 105kg.

The compact, lightweight "bilateral beam" frame is made up of forged, cast, and extruded aluminum parts, just like the YZ450F's. Mass centralization contributes to better balance and handling; credit goes in part to the centre-mounted fuel tank (the air filter is now located behind the steering column).

Credit goes in part to the centre-mounted fuel tank (the air filter is now located behind the steering column). (Photo: France Ouellet)

More powerful and more stable
Right from the get-go, you'll notice the firm suspension on the 2014 Yamaha YZ250F (maybe too firm for my 70kg). The front fork, which is designed to handle big landings and hard braking, has a tough time soaking up bumps and other terrain imperfections. The ride is simply too harsh for beginners and those who want to do a bit of enduro from time to time. A tad more softness, particularly in the early stage of compression, would help make the riding sharper and less abusive.

More physical when changing direction than the outgoing model, the new YZ250F proves just as stable as the YZ450F when launching at higher speed on the run-in to a jump or over the ragged section of a trail. Speaking of speed, the short-ratio 5-speed transmission puts a damper on acceleration, although the engine is now more effective at higher revs.

The 2014 Yamaha YZ250F is clearly more at ease on tight tracks with medium-sized jumps. It's strong out of corners, and produces a strident metallic sound in the process. The DOHC single-cylinder responds immediately to throttle input, so be careful during low-speed manoeuvres in second gear. The kick starter remains, but the engine is easier to start in various conditions (cold, warm or hot) than the previous unit that relied on a carburetor.

Right from the get-go, you'll notice the firm suspension on the 2014 Yamaha YZ250F. (Photo: France Ouellet)

Bottom line
With an all-new engine, an improved chassis, and industry-exclusive innovations, the 2014 Yamaha YZ250F makes a big leap forward. Competitors be warned.

Pros

• Improved ergonomics
• Unique architecture
• More stable than outgoing model

Cons

• Excessively short gear ratios
• Not the most agile