Petrol tap left on or off?

[Veloman]

A simple question, but I am in two minds whether it is worth switching the petrol tap to 'off' between runs. My concern is that if the fuel in the carbs evaporates it is likely to leave troublesome deposits behind. As a petrol pump is used one does not have to worry I presume that the carbs could flood and run neat petrol into the engine.
Any thoughts?

[clarkdw]

If the tank is getting close to full it will flow through the pump even with the ignition off and can cause flooding. Best to leave it off.

[bluehonda]

I wonder if this might be the cause of my hot restart problem that I posted ??