Short update:
I drilled 12 holes, similar to what a guy showed me in the Dirtrider_net forum
This is how I drilled the holes (5.5 mm):
Pressure plate outside
Pressure plate inside
I decided to make some "keyholes" on the outer holes so that oil can easier get to the discs.
I filled fresh oil and then warmed the bike up and started in 4th and 5th gear with lots of clutch*feathering and I really let it scream. No noises so far, but a serious test will follow next week in the woods. I also measure the throwout and its good and like it should be, when the clutch*is pulled I can see the plate lifts fine.
Unfortunately the dragging problem is back. Talked to an experienced motor cycle engineer and he said the plates are sticking, probably they are a few thou too thick. He said ride the damn thing or get a new set OEM friction disks. Its definitely a problem caused by the plates...
Will keep you updated. Thanks for the help guys, you are great !!!