I din't think gas should pour out, but some gas will drip from the bottom of the carb if the choke is used for a extended period.
To start my H (distilate carb) I pull the choke out all the way, crank it two or three times (ruh-ruh-ruh), open the choke, open the throttle 7 or 8 clicks, turn the ignition on and crank it again. Usually it fires and then I use a little choke to smooth it out until it warms up a little.
These tractors are all different so you will have to figure out what yours wants to start. Having a good set of points and the timing set right are critical.