The all-new engine is based on the 2017 YZ250F, and includes a wide variety of updates: an all-new cylinder head, lightweight forged, two-ring, flat-top piston; a shorter, more durable piston pin with diamond like carbon (DLC) coating; a revised piston oil jet, and all-new connecting rod, crankshaft, and counterbalancer designs. Together, these updates improve peak power, power delivery and overall durability.