after about 60 kmh i get a loud clanging from the engine arae valves adjusted and oil changed still noise really loud cant find anything loose and cant get noise by just reving up the engine

 

Only happen when wound out in 5 th gear? How about 1st or second gear @ same revs?

 

only in fifth gear while driving at high speeds 50-60kmh you cant get it by over reving in any other gear

 

Is there anything hanging down, which when its going faster, the wind blows it around? Like a key, or something on a keychain, and when you get going, it bangs around on metal parts.
The motor is eliminated, because it only does it in 5 th., I cant believe the tranny is doing it...you havent had it long enough for that to be trashed.
Oil level correct? proper viscocity?
Does it sound like its related to wheel speed or engine speed?Is this an s or es? If its an s, next time you get the noise, pull up on the shifter(which disengaages the clutch, and the engine revs should drop), and hold it up. Does the noise go away with the revs?

 

the bike is es but the noise is not small it is reall loud this bike has never been abused i have been the only person to drive since new thanks for your help

 

Hmmm you got one of those hard ones that would be best answered by being there to ride it. need better desribtion of the noise. Is it a ticking sound or a knockin noise. is it quite when idling. I think that if you say that you have taken good care of it and motor is in good shape then I might go with a clutch noise cause of the only time it makes noise is when in fith gear (engine under a heavy enough load)
try hookin to a load and drive around and see if get the same kinda noise. The other possiblity is worn cam chain or a tensioner that went bad but it would be noisey when idle too so need more info. ot take to dealer good luck