these are of my 2000 250...not the best pics, but I will post some better ones tomorrow when I have it outside in the day light, unless someone else can post some better ones before then....take note of the tab on the silencer, it prevents it from sliding back...this is a full Pro-Circuit system, I'm not sure what exhaust is on yours...so there could be some slight subtle differences in "where" it sits best, but it's all generally the same...
It sounds as though your jetting is way rich, or your top-end could be weak....it shouldn't be leaking oil/black spooge from there with clean jetting...but since you said you are a "hobby rider", I don't advise you playing with the jetting unless you know what you're doing....plenty of guys on here that can help.