Is a 74 CB750 tank petcock only supposed to flow from one tube at a time when off of the bike. (If you cover the flowing tube, the other side starts to flow.) I presume when attached to the carb inlets a vacuum will cause both to flow at the same rate? (I am used to old Triumphs where everything flows at once, to include oil on the garage floor.) The petcock is new and damn the flow tube in the tank seems long to me, anybody shorten them to get some additional miles before reserve? I just finished rebuilding the carbs and having flow issues to numbers 3 & 4. I am also relatively sure there are some float needle seating issues so I will probably go back in and start from scratch. I tried to find rubber tipped float needles (vitron) but apparently not an option for years prior to 76. Thanks for any input guys, the search function gave some possible answers but it never hurts to ask for more from those who have been there before you........