A get a 9.6v battery, regular 9v batterys DO NOT WORK.
As to the air leaking. If you didn't take the valve out, then cock the market and shoot it a few times. It will give you a better idea to how bad it is.
If its still leaking out the feedneck. Pull the valve out, put a tank o-ring on it and put it back in. Make sure that you put the bigger hole forward or it wont work.
One of you turds is gonna get smacked in the mouth!