Predator,
The fuel input nipple is usually the one closest to the aluminum pump cover on the carb. The steel cover is the regulator. The other port is for the primer bulb, which must be plugged or capped, if not plumbed to the tank. Here is a great website with most of the answers to your questions.

http://www.geistware.com/rcmodeling/glowpower/gas.htm

Dave