The more I think about this I becoming convinced that the diameter & shape of the N3RF (TBS) needle is contributing to the off-idle richness. In a way the G-pop baffles and throttle plate air bleed mods require a slightly different approach to balance things out, & I sure wish I had a definitive Keihin 4 digit needle code interpretation chart.
What I believe may be correct is:
1st digit "N" = OEM identifier
2nd digit = taper profile
3rd digit = length
4th digit = diameter
The above is just speculation, however. And not all that useful without knowing what it means relative to other needle configurations. And it could be total BS. Dunno.
There isn't much to go on for CVK needles. Anyone have a reference chart?
Kawasaki Vulcan 800's also use CVK36 carbs, so there may be other needle possibilities to try...