August 6th
Rick Burgett wins the 500cc Class Motocross at Pine Top Motorcycle Park in Escoheag, Rhode Island. He won 6 out of 7 races to win the 1978 AMA Motocross National Championship.
The Swedish motorcycle Grand Prix was held at the Scandinavian Raceway in Anderstorp.
On the final lap, Honda's Freddie Spencer and Yamaha's Kenny Roberts ran wide and hit the dirt. Freddie got back on the track first, crossing the finish line just ahead of Roberts.
Jim Pomeroy, the first U.S. motorcycle racer to win a World Championship Motocross event, dies in a car accident near Tampico, Washington.
Pomeroy achieved great success in the World Championship and AMA Motocross and Supercross series. He was inducted into the AMA Motorcycle Hall of Fame in 1999.