Clutch dragging on ktm 450 2008 - 2008 KTM 450 EXC-R

Clutch drag??

Do you mean brake fluid for clutch pump or oil for the engine?
If you ask about oil for engine KTM recomend Motorex Power Synt 4T 10W-50.
If you ask about the clutch brake fluid you will need brake fluid DOT 4 or DOT 5.1. See link: http://www.manualslib.com/manual/90432/Ktm-250-Sx-F.html?page=36

Your hub on the shaft - the nut is too tight. The nut is pushing the hub too far on the shaft and making it a drag. Need to back the nut off and torque it at factory spec. That could be somewhere between and 12-15 lbs. This has happened to someone else I know.

Try changing the gearbox oil. Dirty oil will cause the clutch to drag.

The Magura hydraulic clutches on KTM's aren't really adjustable. If it's dragging a little when you put it into gear, there is still air in the system.The proper way to install the fluid is to fill it with a syringe from the bleeder screw until the reservior is full. This insures there is no air in the system. There are kits available aftermarket specifically for Magura hydraulic clutches that come with a syringe and a new line for around 30 dollars. It is a good idea to change the fluid and line every couple of seasons.

How is your clutch? Does it slip or drag when starting out? When you put it into 1st gear when starting out does the bike lunge forward? Hold it in first gear with the clutch in and rev the bike up. See if the bike wants to move forward with the clutch in.It sounds to me like your clutch isn't set right or getting worn out. Much easier to shift at low rpms on a clutch than high rpms. I hope this helps...

all the discs and plates should be the same size did you by a new clutch?

Check with dealer as to correct oil to use in gearbox as I know some models hate synthetic oil!!!