The AMA's youngest age class is Pee Wee Jr., which is a 50cc class, ages 4-6.
Motorcross is competed in, all around the world, at various motorcross tracks
300cc
Motorcross is popular EVERYWHERE but mostly i would say America and the UK
Well, you don't 'play' motorcross! You ride it, and you do this at any outdoor or indoor tracks.
In the 1800s
British
no
Probably motorcross because if a 3 year old child can cycle then that's enough proof for that.
well it depends on who but football players at an average do make more $ than motorcross bikers.
falling down and death
about 70mph
No, but thanks for asking.