I just read a thread on the Rising Sun forum. And this guy had all the same symptoms Major Nelson is having. Going through all the test that you all are doing. And also talking too Jim C.
What they did is switched out the carb and installed a fresh rebuilt carb from Jim C.
And his issue was resolved.
Once he switched out the carb he sent his carb he was having the same issues with to Jim C. To do an autopsy of the said carb. Note: the carb he sent out to Jim C. Was not rebuilt bye him.
But this is what he found. Maybe who knows it
could be a possibility it may be the same problem with major Nelson’s.
Maybe there is an obstruction somewhere in the carb circuit.
Hope this helps.
View attachment 3019113
It has a "freshly" rebuilt carb from JimC on it now. Installed it less than 300 miles ago.