<VV> Carb Problem

[Smitty Smith]

Smitty says:  Let me start this by saying that it hurts my pride to come on here asking for help on this subject because I believe I know as much about HVs as almost anyone out there.  Here's the deal.
  Reassenbled engine that has same carbs mounted as were on there before tear down.  On start up right carb failed to work.  When running on left carb, throttle could be raised with the aid of accel pump above a certain level, where right would then start working.  (maybe 2,000 rpm).  Carb was torn down and inspected.  Bowl fuel level was normal when opened.  Venturi cluster was rodded out and blown out.  No problems noted.  lower body ports and passages rodded out and blown out.  All clear.  Carb reinstalled with same result.  Fuel mist was sprayed around all possible vacuum leak points with no change.  Modulator checks good, crossover is tight, base gaskets and insulator are good.  Second carb obtained which was suspected to be good.  Opened up and cleaned and reassembled.  When installed acted exactly as first one.  I have a test carb I keep on the shelf for engine tests.  Tried it with same results.  
  Although I knew the bowls were being filled I checked fuel pressure at 4 1/2 lbs.  In a fit of desperation I checked compression.  All cyls read 122 to 125.
  What am I missing ?  I have 10 hours invested in this problem.