John how much alcohol are you using in a pass. You should be using a gallon to a gallon and a half. Very much less and your probably running out of fuel. Too much more than that and your probably pushing fuel past your needle seats. Once I had a regulator go bad I burned 3 1/2 gallons by the time I got back to the pits. The belt driven pump is great but not necessary to run an alcohol carb, especially with your tank up front. Try a electric pump and another regulator. You don't want more than 7 psi to the carb. A belt driven pump will pump plenty of volumn for your carb with even less than 7psi.