KDX357 I might stay away from a 500cc 2-stroke if I were you, If you are still going to consider a 500 then do like Dr.Zaius said and TEST RIDE ONE, and keep your fingers on that clutch lever also. I would say a 250 would be good, If you are silly and are not responsiable then get yourself an XR50R 4-stroke, If you are responsible and don't act like an ass and show off until you get used to it then go ahead and try a 250, I have a 1991 XR250R 4-stroke and yes it had enough power for me since I just ride Fire Roads where I can get into 5th and sometimes 6th gear and then the rest of my riding is in tight singletrack trails, But even though the XR has plenty of power for me I now find the Powerband to be rather boring, I would like to have something with a little SNAP to it and a little HIT also, Thats why I am also looking at 250 2-strokes, Just make sure you look the bike over really good before you hand over the cash, Good Luck and keep us posted on your decision, Matt