AMA District 17 MX/SX Class Specifications

updated for 2018 new in red.

AMA Rule book here

Motocross/Stadium Motocross Class names, and qualifications.

Please note that in the 50cc classes there is a specific list authored by AMA for specific machines which are for certain classes.

ALSO note, there are bike height, and wheel sizes specific for all classes, that information is in the AMA rule book.

Specific Rules pertaining to Quad/ATV race equipment is also included in the AMA rule book.

Numbers for Motocross and Stadium Motocross are assigned by the d-17 card processor.

New for 2018 is the age requirement for Amateur riders pertaining to bike size has been adjusted please see notes below this is copied

directly from the AMA rule book.

Class Name AGE Motor Size (cc) *NOTES
50cc (4-8) 4-8 yrs 0-51cc Stock Multi/Auto (class 3&4 AMA)
50 Jr 4-6 yrs 0-51cc Stock Auto
50 Sr 7-8 yrs 0-51cc Stock Auto
65cc Jr 7-9 yrs 59cc-65cc  
65cc Sr 10-11 yrs 59cc-65cc  
85 Jr 9-11 yrs 79-85cc  
85 Sr 12-15 yrs 79-85cc No "A" riders
Super Mini 12-16 yrs 75cc-150cc No "A" riders
Schoolboy 12-16 yrs 80cc-125cc No "A" riders 86cc - 125cc 2-stroke  75cc - 150cc 4-stroke
Schoolboy 2 14-16 yrs 122cc-250cc No "A" riders,  No minicycle or Supermini.
125cc 12* & up 122-125cc  
Open A 12* & up 122cc-Open The minimum age for amateur riders is 12. A rider must be 14 or older to ride a 201cc to 250cc motorcycle. A rider must be 16 or older to ride a 251cc or above motorcycle.
Open B 12* & up 122cc-Open The minimum age for amateur riders is 12. A rider must be 14 or older to ride a 201cc to 250cc motorcycle. A rider must be 16 or older to ride a 251cc or above motorcycle.
Open C 12* & up 122cc-Open The minimum age for amateur riders is 12. A rider must be 14 or older to ride a 201cc to 250cc motorcycle. A rider must be 16 or older to ride a 251cc or above motorcycle.
250 A 12* & up 122cc-250cc The minimum age for amateur riders is 12. A rider must be 14 or older to ride a 201cc to 250cc motorcycle. A rider must be 16 or older to ride a 251cc or above motorcycle.
250 B 12* & up 122cc-250cc The minimum age for amateur riders is 12. A rider must be 14 or older to ride a 201cc to 250cc motorcycle. A rider must be 16 or older to ride a 251cc or above motorcycle.
250 C 12* & up 122cc-250cc The minimum age for amateur riders is 12. A rider must be 14 or older to ride a 201cc to 250cc motorcycle. A rider must be 16 or older to ride a 251cc or above motorcycle.
14*24 14-24yrs 122cc-Open The minimum age for amateur riders is 12. A rider must be 14 or older to ride a 201cc to 250cc motorcycle. A rider must be 16 or older to ride a 251cc or above motorcycle.
25+A 25+ yrs 122cc-Open  
25+ B/C 25+ yrs 122cc- Open  
30+ A 30+ yrs 122cc-Open  
30+ B/C 30+ yrs 122cc-Open  
40+ A 40+ yrs 122cc-Open  
40+ B/C 40+ yrs 122cc-Open  
50+ A 50+ yrs 122cc-Open  
50+ B/C 50+ yrs 122cc-Open  
60+ 60+ 122cc-Open  
Women 12 yrs & Up 99cc-250cc  
4-Wheel A 16 yrs & Up 91cc-Open  
4-Wheel B 16 yrs & Up 91cc-Open  
4-Wheel C 16 yrs & Up 91cc-Open  
90cc 4-Wheel 8-15 yrs 71cc-90cc 2 stroke
  8-15 yrs 75cc-125cc 4 stroke
300cc 4-Wheel 13-15 yrs 90cc-200cc 2 stroke
  13-15 yrs 90cc-300cc 4 stroke
Vintage   8 model years  or older. any displacement No "A" riders