Wierd fuel pressure and hard start issue

What type of pump;mechanical or electric?With or without a regulator?, with or without a fuel return?

I'll go with what George said.
The pressure rise is NOT from boiling in the carb tho,lol. But rather the fuel is trying to boil in the line between the float valves and the pump. You need to insulate the steel supply line, and minimize the amount of rubber in that area. Get rid of any plastic fuel filter you might have. The purpose of these changes is to reduce the heat getting into the fuel line.
Once the fuel is in the bowls, it cannot affect the fuel pressure gauge, as described. It may boil away or evaporate, or leak out, but it cannot cause the pressure to rise in the line.
But IMO you have multiple problems.
>If I had to guess, it would be that some part of the fuel line is in direct contact with something hot, or the fuel is boiling in the mechanical pump that is bolted to the engine.That is the first problem.
>The second is the lack of fuel in the carb 5 days later.At this time of year, the filling stations are probably still stocking winter gas that has a lower point of vaporization. My guess is you got a load of that in your tank, and it is simply evaporating.
Here is a test for that
Put some of that gas in a clear lidless jar, and mark the liquid level with a Sharpie.Set it under the hood somewhere. Come back every 24 hours and note the loss of fluid.
>And finally, if the choke is working correctly, it should still start, allbeit with a long crank time.
>PS I have seen many of those BBSs do this for no apparent reason, and many guys have installed a draw-thru electric pump and just prime the system before every start.