YZ 250 Leaking.I Have Pictures To Look At.?

[donald g]

The bike ran fine until i changed the oil i dont know if i put to much or what but i put 750ml i used the cc on the measureing cup is it not the same? but anyway the bike when you give it gas it boggs down and then all of a sudden it started leaking.I have attached photos of the leak. Also if you notice the oil is real black and i just put new oil in it and only rode it for a few hours.If you look at the second picture air bubbles are coming from the top on that black seal. http://i121.photobucket.com/albums/o236/...

http://i121.photobucket.com/albums/o236/...

Also i noticed the air box was not on the carb all the way.Will that cause it not to idle proper?
http://i121.photobucket.com/albums/o236/deezy411/HPIM1699.jpg

http://i121.photobucket.com/albums/o236/deezy411/HPIM1700.jpg