Very loud valve tick kz 400

I set my valve lash and checked it three times now according to the manual. Its in spec but it still sounds really bad but I'm not sure why. 

Sounds like a very worn cam bucket or chipped valve top to me. By bucket i mean the hollow sleeve that covers the valve and has the shim under it. Quite cheap to try to fit  another one. With that off you can see if the valve top us chipped, if so it's a head off job to replace it. 

Unfortunately KZ400s are not shim-under-bucket; they have threaded adjusters.

The 400 uses rocker arms, not buckets and shims. I’d be inclined to pull the cover off and take a peek.