How do i paint dirt bike plastics?

i dont recomend painting plastics but... if you have to go with
Krylon庐 Fusion you can find it at walmart for 4/5 bucks a can
its made for plastic just make sure you have the plastic clean of any grime, parts cleaner, brake cleaner, mineral spirits are a few cleaners that would work

EDIT: dont listen to the oh buy new 400 dollar plastics guy .. go buy two cans of krylon fusion for 10 bucks and if it fails .. well you only lost 10 bucks right? some bikes just arent worth the trouble to go buy new plastics for and you still want it to look better .. i painted my old yamaha warrior plastics "and im positive they flex more then dirtbike plastics" and the paint hasnt cracked or flaked just make sure to put a few "dust coats" down first just lightly spray all the parts and let it dry for a few min n come back to it n do the final to prevent runs in the paint

it's very hard, and no promise it will last due to the flexing of parts. but if you want to try, scuff it with a gray 3M Scotch Brite, wash it in soapy water, rinse it well, clean it again with a waterborne parts cleaner, apply a plastic parts adhesion promoter, and paint.

this question has been answered before.
you do not paint dirt bike plastic. if you
want to change color you buy new plastic.
trying to paint plastic is not worth the
trouble.

You don't, ever, period. Just buy new plastic.

metallic paint or spraypaint