Now, fitting a new clutch cable thats a different story. For some reason my new cable from Motorworks has doubled the required pressure required to operate the clutch. No kinks or snags and I even took the exhaust off the get all the dimensions set correctly as per BMW. Can't explain that one - can you?
If it is in the correct cable path, you could try taking it off and pulling the cable while it is not attached to see if it is stiff, if it is a stiff cable usually some lube like wd40 does the trick. Also lube up the clutch lever pivot bolt area and make sure the lever can move OK, Also check the freeplay in the clutch lever when the cable is on, it should move just a fraction before 'biting' the cable.
Another thing i done with the brass screws before synchronising was to one at a time take them all the way out, give them a good clean with some brake cleaner or lube, the put a smearing of copper or aluminium paste round the threads (to stop them from ceasing in the future), Then put them all the way in (back them out a bit if engine is going to stall), once they were all done back them out a bit at a time till you got the correct engine tickover, then do a final tune to get them synchronised.