I would definately look into buying a 2 stroke dirtbike. A newer one like my KX250 is all electronic and dont have to be adjusted like old bikes. Look at it this way, your gonna have to frequently replace parts on any bike youll ever own, they're not like cars. If you buy a two stroke, you will have to change a top end every two years if your not racing. If you buy a four stroke, it may last a little bit longer but when its time for rebuild, you could rebuild 3-4 two stroke engines for the cost of 1 four stroke rebuild. were looking at around $600-$800. The two strokes are alot simpler, you dont have to worry about engine oil, only transmission. they are lighter, stronger and the new ones are much smoother than many four strokes. but if you still prefer to buy a four stroke, buy a kawasaki four stroke.. they are much more reliable than any other top brand and they are dependable.