Xpistos

Hi guys I got a k6 sv650 and lately I've been noticing a sort of taperty noise coming from the engine, coming from the valve area of the engine, its only noticeable on tick over but its constantly there, also my idle speed has become slightly iratic (a hundred rpm or so either way) any ideas what this could be? I've also noticed a drop in fuel efficiency (down from 100 to 90 miles to fuel light on)

I tried to video the noise but its just too distorted thanks to my exhaust.

I know I could do better at describing the sound but iI don't know how else to explain it.

Also bikes on 13k miles and never missed a service

Thanks in advance any help appreciated.

Chris