Enter the following codes at the cheats menu:

BROKEASAJOKE - 1,000,000 points
MINIMOTO - 50cc bikes
BIGBORE - 500cc bikes
BRAPP - All bikes
COUCHES - All ATVs
WARDROBE - All gear
LEADFOOT - All machines
WANNABE - All riders
TOOLAZY - All Bonuses
HUCKIT - All Freestyle Tracks NOTMOTO - All Open class tracks
GOOUTSIDE - All National tracks
GOINSIDE - All Supercross tracks
PITPASS - All tracks
IAMTOOGOOD - Pro physics