Hey Joe,

that's not a radio issue but a motor issue.  The amount of energy it takes to START the motor spinning is significantly greater than the amount it takes to KEEP it spinning.  Thus you're able to set a lower idle.  Two things... One, depending on your speed controller, you can set the amount of start up energy it will supply.  Two, you're likely looking to have too low of an "idle".  You really need a moderate idle in the air to supply decent air over the control surfaces for Spins and Stalls. 

I use the "idle down" function for my flying idle.  Leave your trim all the way down and put your Idle Down on a switch and set that to your flying idle.