The Red Bud AMA Motocross National in Buchanan, Michigan is one of the biggest races of the series, and Yoshimura racers topped the podium with convincing wins in both the 450 and WMX classes.At the start of moto 1, Andrew Short added another holeshot to his growing collection aboard his Yoshimura-powered CRF450R. Right behind him was fellow Yoshimura racer and current points leader Ryan Dungey, who quickly poured on the speed and put the pressure on Short.Dungey eventually made the pass for the lead and finished first, while Short finished third. Matt Moss finished 15th in the moto.The holeshot in moto 2 belonged to Ryan Dungey on his Yoshimura-powered RM-Z450. Andrew Short got off to a great start immediately behind Dungey, and the two battled it out on the first lap.Short managed to pass Dungey, but Ryan quickly came back to retake the lead. With an open track in front of him, and plenty of Yoshimura power on tap, Ryan started putting distance between him and the competition. Dungey went on to take his second moto win of the day, and his fifth overall win in a row.Short finished inside the top five taking fourth overall. Moss again finished 15th, and took 14th overall for the day, which is his best finish so far this season.The WMX championship raced for the first time at RedBud, and Yoshimura racer and defending WMX Champion Ashley Fiolek piloted her Yoshimura-powered CRF250R to her first overall victory of the season.Fiolek led both motos wire-to-wire by taking the holeshots and the wins in both races. She’s now only 20 points from the lead in the WMX series.The next round of the 2010 AMA Pro Motocross Championship will be held at Spring Creek in Millville, Minnesota on July 17th.