Nearly every functional part of the engine is new — from the cylinder body, cylinder head, piston, piston pin, connecting rod, crankcase and expansion chamber, to a revised cylinder port shape and updated cylinder port timing. It's a change that is immediately apparent at the first crack of the throttle and throughout the entire rpm range.

A race-proven, highly developed aluminium semi-double cradle frame is engineered to provide the perfect balance of rigidity and flex for competition-ready handling character and composure. Removable aluminium rear subframe is constructed of square-section tubing for reduced weight.

The YZ125X comes equipped with an 18-inch rear wheel, larger rear sprocket, side stand, sealed O-ring chain, new headlight, reserve fuel petcock, and newly adopted scraper between the fork's dust and oil seal, all adding up to exceptional off-road performance.

A racy ‘gripper’ type seat and narrow fuel tank combine with a tapered aluminium handlebar and adjustable mounts to create greater freedom of movement and more comfortable ergonomics for riders.

Cross-country-spec Dunlop Geomax AT81 tyres front and rear are ready to head straight to the races. An 18-inch rear tyre has a taller sidewall to improve comfort and reduce pinch flats.

Industry-leading, fully adjustable KYB spring-type fork with speed sensitive damping uses piston speed to control damping force for super-precise handling and a smooth ride, with minimal wasted stroke or abrupt shocks for the rider – all tuned for the demands of off road racing.