gc350

I havent used my 1999 sv since before chistmas, it didn't rattle then, but has been stood up since unused, i took it for its mot the other day, and cant help but notice that there is a distinct noise, which i am assuming is the cam chain. Do the automatic adjusters get stuck when left unused for a while? How do i sort it if this is the case? Any help would be great.

Cheers