What all can cause gas to run out the carb overflow line.

Question edited for clarity.
Question moved from motorcycles to ATV model category.

Turning over has nothing to do with the carburetor! Your battery is flat. It will need charging.

If the carb is leaking, it is because the float is set wrong or the float valve needle isn't seating properly.

Engines only need three things to run.

A supply of clean fresh fuel (not sitting a year)
A Spark at the right time.
Compression.

You say you cleaned the carb **in** carb cleaner, as opposed to *with* carb cleaner. Did you strip it down, check the float for holes, clean the jets and needles?

Float metering needle is sticking causing it to overflow back into the block has dirt causing a needle to stay open when you shut it off

How do you know they are gas lines? Are they the same diameter? Why are they not still connected?
Does this ATV have a fuel pump? If so they probably connect to the pump.. one is the fuel line and one is a vacuum line... the other probably an overflow.

Could be one of the carb floats is stuck or the rollover caused it to come off its mounting position. As fuel enters the carb, the float rises with the fuel level until it reaches a position that shuts off any more fuel entering the float chamber and prevents an overflow. Fuel level drops, float drops and fuel flows again. Basically like the cistern in a toilet.

clogged carb jets

fuel overflow from the carb is usually caused by dirty or incorrectly adjusted floats and float needle.

I would say that the incorrect of use of gasket goo instead of the proper gasket has spilled into the bowl after assembly and is blocking the main jet --again
when working on a carby , there is no successful "short cut or lazy action"

Check the air cleaner and any ductwork for blockage. (Mouse nest?)

Inspect the fuel system. If the fuel line is out of place and too close to the exhaust or cylinder head, the fuel may be boiling inside the line so you don't get proper flow to the carburetor (this is one possible cause of vapor lock).

Is the choke actuator part of the new carburetor? Verify that the choke is opening when the engine warms up. If it is an automatic choke, inspect the vacuum line and thermostat controlling it. Try removing the vacuum line from the choke actuator and plugging it when the engine is warmed up, then see if the engine keeps running. If it does, the actuator diaphragm leaks when the choke is open.

Check the exhaust pipe for blockage.

If the engine has an EGR system or PCV valve, check those for proper operation. If carbon deposits cause abnormal operation of the EGR valve, the engine will kill when the valve opens too much (about the time the engine is warmed up).

If everything else is good, check the exhaust manifold for blockage by carbon deposits.

it goes into the carburetor, if the float is stuck in the carb the gas will continue to flow out of the overflow hose

sounds like your carb float is stuck and your needle and seat is open allowing the bowl to fill with gas and run out the overflow. take off the bottom bowl of carb and check to see if the float has a hole in it.