I think one lines comes from the bottom of the carbs.. does it hook up on the inside or outside of the pet-cock..
Seems to be going around a lot lately, hope it's not contagious...Good pictures and vacuum and vent hose routing here: http://vfrworld.com/forums/mechanic...eptor-vf500f1-very-serious-running-issue.html
Check your email: I also replied there as well. There is only one line going to the petcock (besides the main fuel line of course). I've attached an edited version of your picture, I hope that helps. you might also look through the How To on my site for more details: Daugherty Motorsports - Tank Valve Petcock Modification