[Wbulk]

I think it's debris in the idle transfer circuit. Carb cleaner in the curb idle air bleeds may blow it out. It's the small slot just above the throttle blade. You may have to take the carb off and blow carb cleaner through the slot. Idle is Ok, then as the throttle opens further you have the problem, which is were the idle trasfer circuit is. Then as you open the throttle further you go into main metering were the fuel goes out the discharge nozzel in the venturi and that works fine.