Yes too much gas could keep it from starting (flooding), Depends on the weather conditions in your area at the time you are trying to start it.
I've seen them leak so bad, gas runs out the tail pipe when it is just sitting, not running.
While you have the carb disassembled clean the chamber where the float needle valve slides up and down. Sometimes varnish gunh can build up inthere and obstruct the full range upward movement of the float needle valve. This would agin cause the flaot needle valve to seat properly and gas to continiously flow through.