i cant decide whether i want a crf250r or a crf450r. im not sure how much power the 250 has compared to my gay 150. how fast will it get to top speed? i want a lot of power but i dont want to much to where im worn out, but i dont want to get tired of the amount of power i have and want more. im 5'10" 140 pounds and ill be getting the bike this spring so i will probably be 6'0" and 160 pounds. need advice.