Hello , i just recently bought an 09' wr 450f and i'm lookin for some info. I bought the bike used and the only thing the guy did was the throttle screw and take the "plug" out of the exaust. The bike runs fine but has a little bit of a hard time starting. What could i do to fix this? also is there any suggestions on what else i should do to my new Thumper? Thanks alot dudes.