Just to let everyone know my own mechanical skill, I have just learned how to change oil in a car & on my bike in the past week.

My 2001 Road King has leaked from the cover of the air filter area down onto a part to which I dont know the name of for as long as I've owned the bike (2 Years now). I bought the extended warranty and took it to the dealer 3 times while the warranty was good and they supposedly fixed it everytime. I Took it to another dealer and they stated, and I quote, "It's just something this particular year Road King is famous for".

Now, I can't imagine that back in 2001 that dealerships sold brand new bikes with active leaks, so obviously they didn't ALWAYS leak.

Another independent mechanic said something was overfilled (cant remember what exactly he said it was), but it leaked after I left that mechanic and the most recent person to service the bike before the independent mechanic was an actual HD dealer.

Now that I've ranted a bit. Can anybody tell me what causes this and how to fix it?

 

Not a mechanic guy, but it sounds like the crankcase is simply being overfilled with oil.

Check your oil both cold and hot levels and adjust accordingly if it is indeed over filled.

 

you're getting oil through the umbrella valves into your air cleaner. It's very common! they are vented to your air cleaner to get re-introduced into the fuel stream and burned up. Many people route the breather lines away from the air cleaner to some place under the bike or to a small catch can to be emptied from time to time. It sounds like you have a bit more than "normal".
Maybe the umbrella valve or valves need replacing? I would assume the Harley mechanics would have checked that out already but perhaps not. There's a lot of info here on this. do a search for umbrella valves or breather lines.