Doubt it is the valves, they just get tighter with wear. They do need to be done if never done before, and at every 32,000 miles.
You need a shim kit , micrometer, magnet, two specialty cam chain tools, or a small screwdriver and hemostat for the one side, tools and torque wrench. A bit of RTV silicone, a service manual and half a day. (and a calculator)
Most likely it is an injector clicking. Injectors are down low valves up high, can listen with a heart scope and kinda tell if up high or low by the injectors.
I have to remember that one, I think I will write it down, Runs like a clock. :cheeky1::cheeky1::cheeky1::cheeky1: We have an all day maintenance day coming up on the 28th, we have a large warehouse to use and everyone brings their tools and works on the bikes. Someone is bound to have a tick, so I can tell them not to worry about it, it is running like a clock. Kit