Help on fixing a vapor lock!!!

The comments in that thread about the fuel are basically correct.
What we call gasoline is mixture of components - some of which is refined petroleum.
It vaporizes over a wide range of temperature depending on the mixture.
All that needs to happen is enough of the lighter components to vaporize and build enough pressure in a bubble to block the flow of fuel.
In this case regulation may be in our favor since it caps the RVP allowed. Higher RVP means more likely to vapor lock.
Running winter fuel on a hot day is when I've had the most troubles with vaporization both at the carb, and in a few cases vapor lock where hardly any fuel was making it to the bowl.
Gasoline Reid Vapor Pressure | US EPA.
Reid vapor pressure - Wikipedia