thats cool man...looks like he was having fun.
I actually had the exact same quad for my 6 yr old...needless to say i sold it. It wasnt stable at all. Every turn he took it looked like it was gonna roll over...he was 6 yrs old and only weighed around 35 lbs. I paid like $220 for it from another guy and sold it cuz i didnt wanna see him get hurt on it. Im gonna probably save up some money and get him a name brand quad thats a lil more trust worthy.
Not bashing you at all or trying to scare you...just want you to be aware of it...