300ex has no spark!!!!

a friend has a 300ex and he rode it down the rode and back and it ran fine. he just got it. when he got back and shut it off he tried to start it again and it had nothing. no spark at all. the plug is good. i dont know what the problem is but it has no spark. havent had much time to look it over so... can any body help me with the problem???????
thank

on mine one of the battery cells blew and it wouldnt start, it was the same thing, it just all of the sudden stoped starting, u might hook it up to another honda battery and see is it starts