93-22RE-pickup

Hey guys I'm new to yotatech so hopefully I'm posting this in the right place. Ive got a terrible grinding sound coming from my engine and can't seem to diagnose the problem which is rare. Here is a video. -Thanks!
P.S.- You'll probably notice the sound doesn't occur on start-up

thook

sounds to me like the chain is rubbing against something. perhaps the cover. how old is the chain kit? oil pump?