The high end needle will cause the engine to flood if giving it some throttle so do try what I said, the low end needle is for idle mixture only and only effects low rpm speed. Once you get it fired up then you can make the low end adustments you need for proper idle quality and mixture. Burybware, when starting the engine I always give a small amount of throttle so the low end needle will have no effect, period. If you start your engine with no throttle then yes the low end needle can make it flood.