Here is my carb synchroniser tool. The gauge on the right is used for the #3 carb as reference.
The second one goes to all the other carb passing thru an aquarium 5 way valve. It is very easy to make and work fine.
How are those gauges working out for you? Looks identical to the 4 gauge set I bought off of ebay then threw in the scrap pile. I tried to sync the carbs on my nighthawk, got everything dialed in, shut the bike off and when I restarted it showed way way out of sync. Connected it to my mightvac as a test, and every single gauge was different. Tried to get them dialed in with the adjustment screw but as soon as a released pressure and pumped it up again I would have a different reading. Tossed it and bought one of these instead.
http://www.ebay.ca/itm/MOTION-PRO-MULTI-CARB-SYNC-PRO-CARBURETOR-SYNCHRONIZER-TUNER-/140820871230?pt=Motorcycles_Parts_Accessories&hash=item20c993f83e&vxp=mtrI hope you have better luck.