Set it wide open, lay the mold on top to heat it up as the lead melts. Make sure the wood handles are not touching the pot as they will burn if left in contact a long time. After the lead has melted, flux the lead to clean it up and then pour the mold several times without hooks to ensure it's heated up well.
The pour tip on the pot will cool down some as it sits. Open the valve to get any cooled lead out and then immediately fill the mold. Keep the mold on a downward slant to prevent lead from splashing into the following cavity. If it does get into the next cavity it doesn't have any force behind it and will quickly cool, forming a blockage to prevent filling the cavity completely.
Leave the pot set on high until the mold is pouring well, then you can lower the temp some. For quick short runs, I use the 8 cavity 1/16 round head production mold and usually get a full fill on all of them. I fill the mold in one continuous pour, starting at cavity one and being generous with the lead, moving quickly to the next until all are filled. It takes a hot mold and hot lead to do this, but get your aim off a little or wobble the mold and you will get some not filled out completely.
Charlie