Here we go! After most of the 450cc motocross machines have been received, we are finally getting our hands on the 250F screamers. This week we had Yamaha invite us out for an evening session at Perris Raceway, to try out their revised 2016 YZ250F. Last year there was no question about who was the best quarter liter four-stroke motocross machine was. A powerful engine character, balanced chassis, and a proven SSS spring fork gave all riders a smile, along with confidence, when turning laps on every track we tried the Yamaha at. This year Yamaha didn’t rest on there laurels, in fact they have over ten revisions to the 2016 YZ 250F: a new piston shape with a flat top design that keep its current 13.5:1 compression ratio, a new piston pin that is 18% lighter and has DLC coating for less friction, thrust washers added to the connecting rod for less friction, a new oil sprayer for increased lubrication, a new crankshaft balance and counter balancer (that changes the balance factor from 47% to 60% to reduce vibration at high rpm), a new ECU setting that is slighter leaner for increased pulling power, an all new clutch boss, shift stop lever, and torsion spring for increased precise shifting and a more solid engagement point at the lever, revised third, fourth and fifth gear dog corners (going from a chamfer to a radius cut) to improve strength, a new muffler bracket that is lighter, a bigger front brake rotor (now up to 270mm from 250mm), revised front fork settings, and rear shock spring change from 56N-m to 54N-m for increased comfort and rear wheel traction.