Seriously a 2 stroke is only as reliable as the owner services it, Most suffer from neglect but these days its people like us who pick em up and sort them out!...
The Honda like others, need top end around 10,000km's and Bottom checked / redone at 20,000km's As for Barrles, they shouldnt need done unless they get damaged or wear excessively, Rings with every top end but no harm in replacing them after 5,000km's
There will be some more tech guys along soon but thats a rough outline... Also check Andy's site the workshop, Tunning section all has usful info well worth sitting down with a coffe and having a read over...