At a terribly muddy Hangtown Classic, the 1975 AMA Pro Motocross Championship started with a win for the late Tim Hart in the 125 Class aboard his Yamaha. Hart was able to better heavy pre-race favorite Marty Smith, the defending champion from Team Honda who was all but unbeatable at that time on his works Honda. But Smith only finished third in the mud at Hangtown. The runner-up over was Belfair, Washington's Doug Raines aboard a Kawasaki. In five total pro starts that are listed in The Vault, the second-place finish at Hangtown was Raines' only top-ten finish.
In the 250 Class, Husqvarna rider Kent Howerton from Texas took the win over Suzuki's new hire Tony DiStefano and Can-Am's Jimmy Ellis. Mike Runyard and Steve Stackable rounded out the top five.
Team Honda's Rick Johnson won the Hangtown Classic in the 250 Class over his teammate Johnny O'Mara and Yamaha's Broc Glover. Rounding out the top five were David Bailey and Jeff Ward. All five were multi-time champions and are now in the AMA Motorcycle Hall of Fame.
Erik Kehoe was one of three Suzuki riders in the top five in the 125 Class. Kehoe got the win over Honda's new hire Micky Dymond, brought in to replace defending class champion Ron Lechien, who had moved over to Kawasaki and up to the 250 Class. Yamaha's Keith Bowen was third, with Suzuki riders A.J. Whiting and George Holland following.
Monster Energy Kawasaki's Ryan Villopoto led the way in Houston's Reliant Stadium over Red Bull KTM's Ryan Dungey and Team Honda's Trey Canard. In 250SX, Racer X contributor Blake Wharton picked up the win over GEICO Honda's Wil Hahn and Red Bull KTM's Marvin Musquin. It would mark the RM-Z250 Suzuki's last win before a four-year stretch that was only ended earlier this season by Autotrader/Yoshimura Suzuki's Justin Hill's success at San Diego.
Defending series champion Ricky Carmichael took the win in St. Louis aboard his Honda CR250 over Yamaha's David Vuillemin and his Honda teammate Ernesto Fonseca. Yamaha-mounted Jeremy McGrath and Kawasaki's Stephane Roncada rounded out the top five.
In the 125 class, Yamaha of Troy's Chad Reed was once again the winner, keeping his East Region run perfect so far. Pro Circuit Kawasaki's Eric Sorby ran second, with Yamaha-mounted Greg Schnell third.