Hey everybody, let me start by saying this is my first post but im not new to the forums. I bought a 2000 wr400 a few months ago, so i came on here to look for the free mods. i found that my bike had all of the except the gray wire mod, anyway to make a long story short i noticed it had a bog, then last week it wouldnt start anymore. i narrowed it down to the carb. here is what i found when i took it off to clean it. This is the A.P diaphragm, i think this is were my bog was coming from. And this is why it wouldnt start, the air jets were completely clog with dirt. I couldnt believe the amount of dirt in the carb. i dont think the prevous owner ever cleaned the air filter, and yes its my falt i didnt change or clean it myself. P.S this is my first bike and i love it, if the wr was still running in that condition its an awesome bike.