Loosen the upper nut closest to the cam chain tensioner main body, but only after you have set the motor in the right position for the correct tensioning of the chain...otherwise you risk releasing some tension from the chain, and then it gets noisy....
There is a correct procedure, probably written up in the FAQ somewhere..
Have a look in there first.
Not sure on the using the "screwdriver on the centre threads" method - can you give me some more info on that one "volz1fsu"
