Engine noise

I have a 76 kz900 that has started to make a rattling noise that does not happen at idle. Crack the throttle and rattle ,rattle. I took the valve cover off and found that the cam chain is really loose at the top guide sprocket. Should it be tight? If so can it be tightened or do I need to replace the chain. Thanks

Have you performed the cam chain adjustment as described in the Kawasaki factory service manual?

I checked the adjustmets and the chain tensioner must have been stuck because now it's fine. thanks