Fountain of Knowledge

This may be one of those questions that deserves a vague answer, similar to 'how long should a novel be?' but I have to try anyway...

How long should the story stretch on before dumping you into the meat of the plot? I'm not talking about not plot or plot introduction before then, but the main plot hasn't gotten any more than hinted at before that point? My dilemma - I'm nine chapters into my story and I've only just started to dig into the real main plot. Only barely started to give more than just hints about what's going to happen. Is that too long? They're short chapters, if that helps, but if I keep them all, they probably won't be once I clean them up and add more description.

Or does it work because I still have conflict before that point?