Reading on drilling the clutch hub for better oil flow and see no mention of doing this on the YZ250F. My sons 09 YZ250F after 5, 2hr harescrambles has lost all clutch lever free play adjustment. We change oil after every race and I readjust the freeplay and after this last race it is adjusted all the way and still no freeplay. I am going to replace the fiber plates and see there are only 5 holes on top of the clogs unlike the WR where the holes are in the notches. Would the YZ benefit from more holes and if so, where ? Thank you !