Went on a basic bike maintenance course with OMC the other night. They covered the head race bearings. Showed us how to balance bike on side stand/back wheel and check for notchy bearings as you describe. One chap had turned up on a GSXR with totally fecked head race, bars would just lock into dead straight as you turned them.
Either way, sounded fairly simply fix to swap bearing in top and bottom yokes. Especially as lights etc shouldn't need to be removed as their not attached to forks, and so they can be just dropped out the bottom. I assume this is true on fazer.
The other thing I was recommended, was to always swap in a taper pin bearing, rather than the default ball and cage bearing, as a taper pin will always last much longer, take much more abuse and are only a few quid more. Again I assume Fazer's are fitted with ball and cage at factory and there is a drop in taper pin replacement, anyone confirm this?