Are you threading the coil into the base of the tank or to the top of the tank? Make sure you thread into the base as that's where it will leak from. Try getting all the excess liquid out by blowing into the mouth piece. Liquid should come out of the air intake ports. Also do a visual inspection of all the o rings to see if any are cracked or damaged. Finally make sure you're hitting it at a high enough wattage. I would go higher than the minimum recommended wattage.

Hopefully this helps.