Power Valve

I recently purchased a '99 YZ 250 in which I currently run MC-1 at 50:1 and will soon be switching to H1R at 40:1. After riding, the Power Valve breather tube drips about a half dozen drops of thick black/grey goo. Is this normal, will the new oil help, or do I need to clean the Power Valve, if so, how often and how do I do it?

Also, should I be bleeding the air from the front forks, if so, how often and how do I do this?

Thanks!