The biggest and most expensive one you can find!
you should get a 80-125
Depends on weight/height. At thirteen I rode a 125 4stroke trail bike and an 85 two stroke racebike
CRF Or YZF 450 is a good choose.... not the x models the not a high strung...
For a 13 year old it depends on your size and your experience with dirt bikes, but an 85 is usually the best size bike and fastest for a 13 year old. Unless you are really tall which you would need a 125.
Try a Yamaha TTR 125 or CRF 150 (not the motocross version).
you should get a 250 trust me i am 13 and 120 pounds and 5' 5" i ride a 250 and it is a perfect size for me. dont get an 85 because they are way to small
19753
Yamaha
Yes
Yamaha XT250
Kawasaki Kx500, any year will do, but the best bike for a beginner is a Yamaha yz490
it depends on how tall you are if your somewhere between 5.3 and 5.5 you should get a 125cc but I can ride a 125cc and im only 5.1 it just depends on how good of a rider you are.if you between 5.6 and 5.10 you should get a 150cc dirtbike.If your 5.11 or taller you can ride any dirt bike you want.