The 650s use a Transistor Advanced ignition.AFAIK they have removable HT(High Tension) spark plug leads(Unlike the CDI CX500s).You can get any decent bit of car plug cable and make a new one by splicing if you wish or use this section to go hunting for most likely an expensive Honda part,
http://globalcxglvtwins.hostingdelivered.com/viewtopic.php?f=17&t=39Also post a request for info on Chopper Charle's forum,
http://choppercharles.com/cs/forums/It's mainly US based so someone should know a supplier there
