I can't think of any reason there should be oil there either. Does it do it at idle? Or do you have to have some rpms
on it for it to happen? If you have oil in the cylinder, how do the front plugs look? You should be burning some oil and the plugs should reflect that. Is it possible that it's coming from somewhere else but appearing to come from the AIS
Pictures would help us to see what's going on. Also take some time to fill in the information about your bike in your profile. This will give us a base to start from!