White_Wolf said:
Why does is ask if I live in CA, I don't but just wondering?
California has restrictions on off road vehicles, more so than any other state.
Like many states all off road vehicles need to be registered with the department of motor vehicles (DMV). They get a special off road sticker that is ether "green" or "red".
Most of the state controlled riding areas restrict the riding season to the winter months for vehicles that have red stickers while a green sticker bike can ride all year.
A vehicle will get green or red stickers based on if they meet the EPA requirements or not. Bikes that were manufactured prior to 2003 (2002 and older) are grandfathered into green stickers. Starting in 2003, no two strokes can have a green sticker and many of the "MX" style four stroke bikes do not qualify.
The restriction on the riding area will obviously have a major impact on the selection of a bike if you intended to ride on public lands. Most of the MX tracks used in competition are private and off road registration is not required.
As for your son's needs:
Dirt bikes come in two basic flavors: "MX" and "Off Road".
The Off Road bikes are meant for more casual riding on established trails. Great bikes for beginners and people that are not riding aggressively. They will typically have a lower seat height to accommodate shorter people. Electric start is common as are headlights and taillights. (allows night rides)
The MX bikes are built for race. They will have high performance engines, which means that they can be a lot harder to start, require premium gasoline and are much more critical on regular maintenance (including frequent engine overhauls). The MX bikes cost a lot more than the off road versions.
If he intends to race he will want a MX bike. If racing is a few years off then he might be better off starting on a smaller bike and then upgrading in a year or two.
For a MX bike a Yamaha YZ125 (two stroke) or a YZ250F (four stroke) would be good bikes. The two strokes are easier to maintain but they are also a bit harder to learn to ride. To get into your price range you would need to go at least 10 years old.
If you would prefer to start with a cheaper off road model then a Yamaha ttr-225 would be a good choice. Since it was a cheaper bike to start with you should be able to get one in your price range that isn't more than 5 or 6 years old.
Rod