I've never had to do what you are doing. You need to find out why you are having issues. Adding a return line is not that simple, it takes some engineering.
Do you run gas with EtOH? Unfortunately, that's all we've got in CA. I plan on adding a heat shield under the carb and some DEI heat wrap over the fuel line near the header. If those don't cut it, I'm gonna have to engineer something. As I said, the issue is very minor, but then again, it's not 100 degrees yet...