Dry carb

[droptop]

I was sorting out a few niggles with my spider yesterday and one of them was hard starting after being parked up for a few weeks.
I found the automatic choke mechanism had become detatched from the carb and to reattach it, I had to take the top off the carb.
I found the float chambers empty of fuel after the car was idle for the last four weeks.
Now, I don't imagine it was sucked back out through the needle valve nor do I imagine the carb body is porous but where did it go? Evaporate?
The car is parked in the garage and the weather hasn't been exactly hot here so I'm puzzled.
I did discover the fuel pump is weak though and there was a slight misfire at high RPM which I'm inclined to attribute to that.
I've replaced the pump, checked and set the float levels and I just don't know what else to look for.
Anyone experienced this?

[HFStuart]

The fuel in the bowls does evaporate slowly - it's vented to air via the jets. 4 weeks is long enough for it all to go.

Normally a few seconds of cranking is enough to refil them.

[droptop]

I was forgetting it isn't a sealed system!
I just finished fitting the new fuel pump which in reality was a Fiat item so the spigots were more suited to a RWD fitment but with new longer hoses, it went on and after maybe five seconds cranking, the engine fired and ran.
I replaced the fuel returnhose between the carb and the steel fuel line as well since this was the only flexible pipe in the fuel system I hadn't replaced.
Having a working choke is of course a major contributing factor to the ease with which the car started, but being able to properly deliver the fuel to the carb in the first place is the secret of my success .
Just slurping coffee at the moment then back to the lab. to check out the brake issues.
I'm convinced the front brake portion of the master cylinder is defective but now the car is running, I can at least check the operation of the servo as there may potentially be an issue with it or the non return vacuum valve.
I'm suspicious of the master cylinder as the back brakes seem to do most of the work and certainly produce the most dust.
Time'll tell.