83 Big Red. Issue: Starts second pull with choke when cold. Runs and idles fine for about 5 -10 minutes then dies. Acts like a vapor lock starving for fuel but pretty sure it isn't because then it will idle high with choke fully engaged. Any throttle response kills it. Let it sit for awhile and starts back up and runs until hot. Preventive maintenance nut. Air filter clean. Carb has been rebuilt twice (me and shop). Same issue. Could it be something electrical like a CDI/coil failing when it gets too hot? Thanks.