honda xl185s help i need it running tonight!?

[Caleb]

i have a 1980 Honda Xl 185 and the gas is not going to the carb. i have the gas on i tried putting it on reserve also i'm not sure what is happening, i changed the throttle cable 3 days ago and ran it, i think it was just running off the gas that was in the system then the next day it was stalling a lot cuz it was low on gas so i filled it up too the top and I couldn't get it running even wen i tried role starting it. I checked the gas filter i have on it and there is nothing in it so something isn't working right please tell me how i can fix this( the petcock does leak a little but i took the gas hose off and tuned the petcock to on and gas was running through it fine)