I have a 2004 YZ250, i bought it brand new and it is completely stock, the thing goes through plugs like nothing else, the plugs are oil fouled terribly, and this only happens when the bike is cold, if it is warm it runs fine, but it does smoke alot. I'm assuming that it's running way to rich and maybe i should turn my main jet out? Or completely retune my carb? Any Help is appreciated. I use yamalube 2r at 32:1 but i recent switched to Maxima Formula K2 but haven't ran enough to see any results. ANY HELP IS APPRECIATED. thanks