Yes, as Kernow said, you always check the float level when rebuilding a carb.
Early floats had metal arms that you bend to set the float height.
Later all plastic floats require that you change the thickness and/or number of fiber washers between the valve and bowl lid to set the float height.
As for why it only leaked when hot... who knows. Temperature change in the carb should not have affected it but there could be other things going on such as debris that worked loose when the engine bay got warm. Be sure to replace the rubber hoses going to the carb and install a disposable fuel filter right before the hose connects to the float bowl lid.
