Talk with a salesman, let them help determine what size dirt bike is appropriate for your. Be sure to tell them what you will be doing, play riding, racing, dual sport rides, etc. Select a model that is suitable for your skill level taking into account the bike's handling, power and size. Sit on the bike to make sure it is the right size and test ride each bike. Also, consider buying a used dirt bike.
lose weight then buy a motor bike (Really stupid answer i know) i don't know why i put this up there.......
Snowboard because its better than a dirt bike.
Buy a USED 250 dirt bike.
For a 2-stroke dirt bike all you have to do is, buy a taller cylinder, and buy a longer crankshaft.
Not usually. Some dealers will give you a helmet when you buy a bike, but nothing else.
One can buy a mini dirt bike from the local bike stores. Sometimes local community auctions also feature variety of mini dirt bikes for very reasonable price.
Auto Zone
you don't!!
Ebay, Craigslist, a dealership
buy a Giovanni kit bike and follow the instructions
50cc dirt bike may be available at a bike specialist store, but very unlikely. Most 50cc dirt bike are seen online for purchase only. For example eBay and Amazon.
Dirt bike parts can be purchased at several retailers. These retailers include Service Honda, Rocky Mountain ATV/MC, Dennis Kirk, and local dirt bike dealerships.