I have this carb on a 425 Nailhead. If I let the car set for more than a couple days, I have to pump the heck out of the gas pedal to get it to finally fire. The longer it sets the more I have to pump; up to thirty times. It is like the gas has drained from the carb. I had heard somewhere that there could be an unused port or hole that should be filled with silicone caulk in certain applications. I have the carb off right now, doing some other work on the engine. Can anyone help me out with suggestions?