Weak spark can cause this too and should be checked.
What is your air screw set at? When you say you air filter is well oiled... what do you mean?
Try this... drop the main jet one size. And my guess is that your needle is also setting too high in the saddle! Try raising the clip one notch on the needle. This will take your Top (Main) and Middle (Needle) range leaner by one step. Your pilot sounds fine, but it may also be running rich.
Make notes of what is in there and what the needle is set at before you start messing with the jetting. This way you have a baseline. Everytime you make an adjustment... document it and the results.
If you can't get there from here... there is always slide cuts!

Nah... we won't go there...
Personally... I think Plug Chops are a pain in the @ss... I know if it's right by the way it reacts and the color of the plug. If you really want to know... the procedure is all over the internet. Basically.... Warm up your bike... change to a new plug.... run wide open for 10 seconds, push the kill switch and pull in the clutch at the same time. Pull the plug, chop off the metal surrounding the insulator and look at the ring. Is it narrow like a pencil line or wide and black? And this only tells you how it's running on the main!

Some plug chops are pictured in the Gallery if you wanna take a look see...