Man... it sounds like an interesting problem. Time is hard for me to come by right now. I did find this thread that maybe will help you out...
http://www.gz250bike.com/forum/showt...ighlight=spark
Maybe it'll help... Keep us in the loop here.... I've just went through some electrical issues myself and have the schematic at the ready..... if you're still having problems in a couple of days, I'll try to make some time
Brad