Apparently it wasn't a kawasaki engine it was a watercooled Honda 80cc trail bike engine. The bike was sprayed green though, so to my 8 year old brain that obviously = kawasaki. The lad who rode it, Andi Notman is doing well in Road Racing now.
I'm not the best to help you with knowledge about them, i was only 8 years old when i had mine so all i can remember is being chuffed to bits with it. Was the closest i could get to my hero Eddie Lejunes bike. Was certainly lots about in the areas/clubs i rode at. Not sure you'd get your cash back selling it for a youth rider as theirs far superior bikes nowadays but its defiantly worth it from a collectors point of view. I'd have my old one back just for the fantastic memories.
If theirs anything specific you want to know, let me know and i'll ask my dad. Think he built a few in his time at the Honda dealers.