2000 fatboy is leaking oil under filter, I have checked serface that o ring seals to and no imperfections seen. changed filters (brands,chrome,not chrome) Still leaking. I put small rag between filter and case and it catches oil for a bout 100 miles then starts dripping. Help!!!!!

 

Something just has to be scored or warped if it's leaking at the filter-to-adapter junction. Maybe take the adapter off the engine and replace it if you can't stop the leak any other way. You say it's coming from that mating area and you have tightened the filter down and even changed filters........don't know what else it could be. There is nothing there but a rubber gasket on the filter and a (supposedly) flat surface for it to contact. There is only one moving part on there and it's the nut in the center of the adapter the filter screws over.

 

Make sure you are not getting residual oil from your oil change. I chased a drip from my filter through a 1000 mile trip and two washes. I just never got all the residual oil that had ran down the front of the bike (it was pretty messy). I was on the verge of swapping filters, and finally took the voltage regulator loose and really cleaned the entire front end and have not had any issues since. Next oil change I was much more careful.