Let's try this again, since my reply vanished after this place went down yesterday. (That really sucks...)
Anyway, I said that early JAKQ, early Sunvulcan, Bioman, Changeman, Flashman, Maskman, Liveman, Turboranger, Jetman, Megaranger, GoGoFive and Timeranger are basically what you're looking for. They don't focus on kids too much; they'll have kid-oriented episodes thrown throughout, but nothing quite on the level of a Fiveman or Zyuranger. (Although, shows like Dynaman and Fiveman were teachers, and Zyuranger was a fairy tale sort of thing, so it makes some sense that these shows feature kids frequently.)
And what's funny is that a lot of modern shows don't have a lot of kid guest stars, but the content of the shows themselves is more juvenile than ever. And the cast members themselves are so young, they're practically kids, so I guess why bother with kid guests is the thinking there.