ok guys this is my first post so go easy on me. i'm buyin a ttr90 from a friend of mine because a bunch of us like to screw around on the weekends that we're not racin and have what we call "pit bike nationals". what are some free mods that i can do to start off with before i start throwin money into it? i read before something about the air box and i also read a few other things but can some one tell me how? and also how do i position the stock rear shock for more ground clearance?