I have been working on a carburetor again. I am using basically the Duclos design. I am having a problem with the engine running for 10-15 seconds and then dying. It is running our of fuel. My question is what should I be changing? I have been trying bigger and smaller throat diameter. What I currently have is a 1/4 dia throat with a #10 (.190) fuel rail with a #60 jet dia. Should I be trying smaller of larger throat? Should I use a bigger or smaller jet. My modifications do not seem to be obtaining the results I am expecting. I would think that less area between the fuel rail and the throat dia would improve things to get more velocity but it does not seem to be working.