iv been riding dirtbikes my whole life and re built them and everything. id say go with a 125 two stroke yamaha suzuki honda or kawi it doesnt matter aslong as its like 2000 or newer. honda is the only bike with aluminiumn a aluminum frame up till around 05 when other brands started doing it. do not buy a four stroke yamaha any older than about 06 cause they were junk. and dont buy a fourstroke honda or suzuki any older than 04. but remember, hondas require mkore often fluid change and have tranny oil and engine oil one on each side and must be changed about every 5-8 hours. two strokes are actually pretty relable. when the top end blows its only about 100-200 bucks to re build but if a fourstroke blows upyour looking at possibly over 1000. (i just blew my crf 450 up two weeks ago). so if you dont want to spend tons of money and want to beable to fix your bike on your own get a 2 stroke 125. much simpler than a 4 stroke. but if thats not a issue for you id get a crf 250. there great bikes. and if you have any questions just ask and i prolly can give you a answer.