Hows everybody doing?

I have an 04 RK EFI, serviced regularly with just under 11000 miles. Recently, theres been a developing rattling sound more pronounced on the right side. I remember when the rumble was clean and aggressive, now there's a heavy breathing/ rattling sound...

Anybody got any ideas before i drop serious cash on diagnosis?

Much obliged.

 

Remove the cam cover a inspect the chain tensioners.