cam shaft on a 2003 rinco 650 4x4

[BecSneed913]

Ok, so I bought this atv, and after getting it home and running it for a while an engine noise developed. It was not constant but very annoying. After reading several post I thought it was timing chain tensioner and decided to tackle the job. I have the head off and timing chain exposed, but it seems good and tight. One area of concern I have, is to the right of the lobes is some piece of the cam shaft that seems to have lots of slack in it. It might be called the decompression cam. If so, is this thing supposed to be able to rattle around? If not, that may be my problem. Are there any clips or something of the sort that are supposed to lock it in tightly. Any help would be greatly appreciated. Im no mechanic but can follow directions.