Re: Kentucky km550 tuners lousy ?
If the tuners are the same Gotohs as the ones on the 505, which I'm fairly sure they are, then they're fine. Short of forking out a fortune for Waverleys, most Schaller, Gotoh, Grover etc are pretty much of a muchness. Small differences that are so subjective that you'll get supporters for each of those brands.
Tuner issues are more often caused by something else: incorrect post-hole spacing, nut binding, tuning down instead of up, incorrectly executed string windings on the posts...
I guess your particular set of tuners may be faulty, but as a group, those tuners are fine. I'd check those other factors.
Blue Chip picks, Tone-Gard