Has anyone got the information for setting the cam chain adjustment for a gk 76 ?

GK76a engines have an automatic cam chain tensioner fitted as standard. If the chain's noisy it could mean either the tensioner's spring has broken, the auto mechanism has jammed or maybe one of the chain guide-blades have broken?
I don't know if the chain itself can stretch to the point that the auto tensioner runs out of adjustment, (as I'm not an expert on GK76's, or 4 strokes for that matter), but having checked the operation of my GK76's OEM auto tensioner those are plausible reasons. HTH.

Or are you refering to something else entirely?

Auto tensioners on all Suzukis of this era had weak auto tensioners. And if the chain has stretched then the tensioner can lock out at max

Thanks for clarifying Mr Stripes.