sounds like you have a float that is stuck. when the float stcks down it allows more gas into the carb. you may need to pull the carb to clean the float needle and seat.
First it depends on where it is leaking and what is leaking. IF it is leaking fuel out the drain hose, then remove the shut off screw from the bottom of the float bowl. You can clean this out using carb cleaner with the straw. Carefully inspect and clean the shut off screw. I have polished these with ultra fine emery cloth. this should stop the overflow leaks. Also, you might want to pull the float bowl off and make sure the float is not stuck allowing fuel to continullay flow into the bowl. IF it is allow air to leak in, then check the carb top gasket and the intake boot for damage.
fuel leaking out drain hose while driving Honda z50
open up the float bowl drain screw and don't forget the reservoir (bottle) under the drain tube below that the hose that connects to the petcock off the drain screw.
There should be a small brass screw on the bottom of bowl close to the drain hose see if it is opened. If no the rubber O ring on that screw has degraded and needs replaced
The "dry" setting is 17.5mm +/- 1mm from the base of the carb gasket surface (without gasket) to the center of the float (furthest point from the pivot point of the float). The "wet" setting is 3mm below the gasket base of the float bowl. to accomplish this you fit a hose to the bowl drain and loop the open end to extend above the float bowl/carb surface. Open the drain screw and measure the fluid level from the bottom of the main carb body.
Possibly air conditioner drain hose is clogged
The only hose connections at the firewall that contain coolant are the connections at the heater core. You either have a loose clamp or the compression fitting between the steel and metal parts of the hose itself are leaking. If there is coolant leaking out of an drain at the bottom area of the firewall, there's a good chance that it's leaking from the heater core itself, through a drain pipe which is the same drain pipe that removes water condensation from the air conditioning.
AIR CONDITIONERS ARE SUPPOSED TO LEAK. ALL YOU CAN DO IS ATTACH A HOSE TO THE DRAIN AND RUN THE HOSE SOMEWHERE WHERE IT CAN SAFLEY DRAIN.
fair chance the drain hose for the a/c has come out of where it is supposed to plug in.
Usually any fuel leaking out of the carb like that would be an indication of a sticking or defective needle/seat and or float mechanismn. Clean thoroughly with carb cleaner and or rreplace needle/seat/float and bowl gasket.
According to the Clymer service manual, "The fuel level should be 0.53-0.57 in. (13.5-14.5 mm) below the piston valve center mark on the float bowl." (The "piston valve center" is marked near the round protrusion on the back of the carb, the side with the fuel lines)
That hose is the drain. It can just end somewhere safe, below the motor and out of the way.