[1] The AMA made a controversial decision allowing only American citizens to compete for the motocross national championship.
[1] The decision would exclude the defending 500cc national champion Dutchman Pierre Karsmakers who, was credited with helping raise the level of American motocross by stressing the importance of physical fitness and machine preparation.
[2] Although he was excluded from the overall results, Karsmakers competed for Yamaha in the 250cc class and won three of the nine rounds.
[1] Despite not having won a race overall, Can-Am's Gary Jones rode consistently to secure his third consecutive 250cc national championship riding three different brands of motorcycles.
[3] Can-Am hired second-ranked Marty Tripes away from the Husqvarna team before the last race of the season.