1973 AMA Motocross National Championship season

The 1973 AMA Motocross Championship season was the 2nd AMA Motocross National Championship season.

The sport of motocross experienced explosive growth in 1973 and motorcycle manufacturers sought to capitalize on the expanding market with all four Japanese manufacturers fielding factory-backed teams alongside their European counterparts.^[1] Pierre Karsmakers from the Netherlands dominated the 1973 500cc national championship, winning seven of 12 AMA Nationals and claimed 17 victories in 36 races overall.^[1][2] Karsmakers is credited with helping raise the level of American motocross by stressing the importance of physical fitness and machine preparation.^[2] 1973 marked a turning point in American motocross when Jimmy Weinert became the first American rider to defeat the then-dominant European riders in the Trans-AMA Motocross Series at Lake Whitney Ranch in Texas.^[1][3] His victory showed that the level of American motocross had begun to compare with the level of European motocross.^[3]

As in the 1973 season, after the season-ending 500cc race on September 9, American riders competing for the AMA national championship continued to accumulate points counting towards the national championship while they competed in the 1973 Trans-AMA motocross series, which began on September 23 and hosted visiting European riders from the Motocross World Championship.^[1] Although Karsmakers was a Dutch citizen, he was competing under an AMA license so, he was listed as the "Top American" finisher in the Trans-AMA series.

After winning the 1972 250cc national championship on a Yamaha, Gary Jones was hired by Honda to help develop their new Honda CR250M motocross bike for the 1973 season.^[1][4] He did so successfully to win his second consecutive 250cc national title.^[1]

Round	Date	Location	Winner	Team	Report
1	March 10	Daytona International Speedway	Pierre Karsmakers	Yamaha	Report
2	May 6	Opelousas, Louisiana	Mike Hartwig	Husqvarna	Report
3	May 13	Hialeah, Florida	Pierre Karsmakers	Yamaha	Report
4	May 20	Olive Branch, Michigan	Mike Runyard	Suzuki	Report
5	June 2	Atlanta, Georgia	Pierre Karsmakers	Yamaha	Report
6	June 10	Adelphi, Ohio	Pierre Karsmakers	Yamaha	Report
7	June 17	Lake Whitney Ranch, Texas	Brad Lackey	Kawasaki	Report
8	August 12	Lake Whitney Ranch, Texas	Pierre Karsmakers	Yamaha	Report
9	August 18	Pocono, Pennsylvania	Mike Runyard	Suzuki	Report
10	August 26	Sligo, Kentucky	Pierre Karsmakers	Yamaha	Report
11	September 1	Alabama International Motor Speedway	Pierre Karsmakers	Yamaha	Report
12	September 9	New Orleans, Louisiana	Brad Lackey	Kawasaki	Report

Round	Date	Location	Top American	Team	Report
13	September 23	Springville, New York	Pierre Karsmakers	Yamaha	Report
14	September 28	Philadelphia, Pennsylvania	Pierre Karsmakers	Yamaha	Report
15	October 7	Lexington, Ohio	Pierre Karsmakers	Yamaha	Report
16	October 14	Washington, Indiana	Jimmy Weinert	Kawasaki	Report
17	October 21	Atlanta, Georgia	Pierre Karsmakers	Yamaha	Report
18	October 28	Orlando, Florida	Brad Lackey	Kawasaki	Report
19	November 4	Houston, Texas	Jimmy Weinert	Kawasaki	Report
20	November 11	Phoenix, Arizona	Pierre Karsmakers	Yamaha	Report
21	November 18	Puyallup, Washington	Pierre Karsmakers	Yamaha	Report
22	November 25	Livermore, California	Rich Thorwaldson	Suzuki	Report
23	December 2	Orange, California	Pierre Karsmakers	Yamaha	Report

^{[5] [6]}

Round	Date	Location	Winner	Team	Report
1	March 10	Daytona International Speedway	Bob Grossi	Husqvarna	Report
2	May 6	Opelousas, Louisiana	Jimmy Weinert	Kawasaki	Report
3	May 13	Hialeah, Florida	Gary Jones	Honda	Report
4	May 20	Olive Branch, Michigan	Jimmy Weinert	Kawasaki	Report
5	June 2	Atlanta, Georgia	Marty Tripes	Honda	Report
6	June 10	Adelphi, Ohio	Gary Jones	Honda	Report
7	June 17	Lake Whitney Ranch, Texas	Gary Jones	Honda	Report
8	July 1	Tooele, Utah	Pierre Karsmakers	Yamaha	Report
9	July 6	Los Angeles Memorial Coliseum	Marty Tripes	Honda	Report
10	July 15	Baldwin, Kansas	Pierre Karsmakers	Yamaha	Report
11	July 22	Delta, Ohio	John DeSoto	ČZ	Report
12	July 29	Unadilla, New York	Pierre Karsmakers	Yamaha	Report
13	August 12	Lake Whitney Ranch, Texas	Tim Hart	Yamaha	Report
14	August 18	Pocono, Pennsylvania	Rich Thorwaldson	Suzuki	Report
15	August 26	Sligo, Kentucky	Gary Jones	Honda	Report
16	September 1	Alabama International Motor Speedway	Gary Jones	Honda	Report
17	September 9	New Orleans, Louisiana	Gary Jones	Honda	Report

^[5]

500cc[7] Pos Rider Team Points 1 Pierre Karsmakers Yamaha 2659 2 Mike Runyard Suzuki 1427 3 Peter Lamppu Kawasaki 1126 4 Gary Semics Husqvarna 1079 5 Brad Lackey Kawasaki 999 6 Tim Hart Yamaha 888 7 Rich Thorwaldson Suzuki 769 8 Mike Hartwig Husqvarna 756 9 Tony DiStefano ČZ 566 10 Wyman Priddy Kawasaki 539

250cc[7] Pos Rider Team Points 1 Gary Jones Honda 1445 2 Rich Thorwaldson Suzuki 1086 3 Bob Grossi Husqvarna 900 4 Jimmy Weinert Kawasaki 878 5 Tim Hart Yamaha 710 6 Marty Tripes Honda 603 7 Pierre Karsmakers Yamaha 494 8 Gary Chaplin Maico 486 9 Dewayne Jones Honda 485 10 Jim Pomeroy Bultaco 465

• AMA Motocross web site Archived 2016-02-13 at the Wayback Machine
• Motocross National Championship web site Archived 2016-02-11 at the Wayback Machine