mky 13yo rides the hell out of my 03 blaster. he's a little timid when it comes to speed and riding in the power band for sustained amounts of time but he tears it up on the hills and dunes. i dont think i would put my 9yo on it alone without first wrenching in the throttle stop quite a ways. but he could probably handle it on some relatively flat areas.
2004 400EX in red, the faster color.
2003 Blaster in black/red. VForce reeds, 14T front sprocket, FMF fatty pipe, Power core silencer, K&N filter.