ok so heres the story and i hope someone can help. ive searched and searched and searched...

i recently got a 1999 cbr 600 f4. the guy converted it to a f4i im assuming just the fairings..

it is very hard to start . usually have to give it throttle to get it to run, and seems like it will hold idle after it starts for like 30 seconds or so then dies down and stalls then it wont start again.. but if i remove the airbox completly i can get it to start again and somewhat hold idle . while doing that .. oil started comming out one of the hoses that hooked to the airbox. i have never worked on motorcycles before so i am completly lost. anyone have any idea what could be wrong? ive read about emissions,fuel,carbs ect.

any help would be great guys. I appreciate it