I can't believe there isn't a single reference to this on the Internet - an ctual GoogleNope!

Dunno - didn't know anything, the main character
Dono - the one who did know everything and solved a lot of problems ignorance got the characters into, led by Dunno
Bendem & Twistem - the mechanics
Treacly Sweeter and Roly Poly - the fat kids
All the girls had names i thought were beautiful like Cornflower.

?? Ring any bells?

In Hungarian all I remember was Nemdutomka (Dunno) and that the people were as small as little bitty cucumbers - mint egy ici pici uborka...