Jetting problem?

I have a 96 CR250. Love it, but it seems to be smoking alot and excessive amounts of black goo is coming out the spark arrester. I'm running a standard 32:1 mix of honda synthetic oil. I've also not been able to get it to idle at all without constant revving of the throttle. I've adjusted the pilot valve all I can with no noticable difference. It does seem to flood out easy, as I have to hold the throttle open to start it up most times. But it does always start after a few kicks, and seems to have plenty of power and is still fast. I bought the bike a few months ago and it's always been doing this so I'm still trying to fix it myself. any suggestions? thanks.