i am goin to get a new bike and dont know whick to get. Im 5'8 140lbs, i will be ride mx sometimes an i dont know if i should get a 125 2s or a 250 4s i was lookin at the thumpers but a lot of people have been telling me that changing the valves are a nightmare. But on the 2s i heard you have to rebuild the bike all the time, very often. And i dont really want to be re building the bike instead of riding. I know the 4s are more expensive but since you have to rebuild the 2s all the time wont it be the same. idk