Question for the carb gurus (85 Honda 450 Nighthawk)

[WAP]

After successfully synchronizing the carbs on my GS using a homemade Carb Balancer, not unlike those discussed in various threads on this site  , I decided to do the same to my girlfriend's 450 Nighthawk. Problem. I can't for the life of me find a second vacuum port. The vacuum port on the left hand carb is easy to spot, it's at the end of a tube from the petcock. No such luck on the right. My Clymer manual is not specific on where to connect a carb balancer, only to follow the directions for the carb balancer (not much help since it's homemade). The Clymer manual DOES, however, state to remove two plugs (one on each side) before connecting the balancer. These plugs are located on the cylinder heads, directly above the inlet tubes from the carbs. But Clymer doesn't elaborate. These plugs are simple screws, not the vacuum ports i was expecting. So what the heck do i do?  Does a dual-carbed system necessarily have to have TWO vacuum ports (probably a stupid question, otherwise what do you balance?)?

[scratch]

Hondas require a threaded tube to be screwed into ports on either the carb boot or the head; these ports should be plugged with a screw (usually philips).

[WAP]

So if I'm understanding you correctly, I need to figure out a way to connect the leads from my carb balancer (simple aquarium tubing) into these (indeed philips head) screw ports? Can i leave the vacuum hose to the petcock unplugged during balancing? Any suggestions on obtaining/manufacturing a threaded tube like this?

[scratch]

Order these: http://www.carbtune.com/carbaccs.html