2017 Yamaha motocross range

The 2017 Yamaha motocross range has been unveiled, comprising the YZ250F and YZ450F four-strokes and YZ250, YZ125 and YZ85 two-strokes.

The YZ250F has been given a thorough engine update, which includes the following:

1. A new cylinder head and intake system. There's revised intake geometry for additional downdraft effect, matched to shorter intake funnel in the airbox for improved top-end power. Inside the head, more aggressive camshaft profiles and valve springs boost output further, while larger valve seats ensure excellent sealing and reliability.

2. The diecast crankcase features a new heat treating process to increase strength. Inside, a new nickel-chromoly steel connecting rod offers additional durability to handle the increased power output.

3. New gear dogs, revised gear tooth designs and a host of smaller changes are claimed to create a smoother overall transmission with improved shifting, as well as a stronger overall powertrain for improved durability.

Meanwhile, on the chassis side, revised engine mounts and a reshaped swingarm pivot section of the aluminium frame are aimed to improve lateral rigidity, while 5mm lower footpegs help lower the rider’s centre of gravity. There are also revised suspension settings front and rear to match the chassis updates.

Like the 2017 YZ450F, the YZ250F has a redesigned air cleaner cover to help prevent contact with the quick-release airbox fasteners. It provides tool-less access to the air filter, positioned at the front of the bike to avoid roost from the rear wheel.

The YZ450F also has an updated rear brake rotor, new Dunlop MX35 soft/intermediate tyres and new graphics.

As for the two-strokes, which don't have quite the developmental love they used to, the YZ125 and YZ250 have new 270mm front discs (up from 270mm), while the YZ85 remains unchanged.

Yamaha Motor Australia is yet to provide pricing or on-sale details.