Oil leak 2006 CBR1000RR
 

Need some help I've got a small oil leak once the engine warms up seems to be coming straight from the 3rd exhaust valve right at the header. Need some advice on what it could be and steps I should take next to fix it. The bike is running great otherwise. Could it be a problem with the valve internally? loose bolt somewhere? I like to try and do my own maintenance to learn more myself and really don't want to take it into a shop unless I've exhausted all resources and try everything myself. Any good mechanics have some ideas?

Maybe a compression test might show something up