if one cleans the bike, it will be easy to see where oil is coming from - on a black engine, I wipe a paper towel around head & exhaust every so often to check for leaks
engines should remain reasonably dry & clean unless something is wrong
Installing a CR Machine Manufacturing billet cylinder head fixes the cylinder head oil leaks.
Exhaust port leaks can be largely solved by carefully filing the exhaust muffler flange perfectly flat and then installing the muffler system with Permatex Ultra Copper silicone sealant applied to the exhaust gasket.