What happens if the throttle esc only works in the thottle( #3) slotof the reciver but not in the other slots.</p>

This question is a little vague. Why would you want the throttle on another channel? Have you tried to use the ESC in another channel and discovered it does not work? The biggest differense I can think of is the other 3 channels usually used for rudder/elevator/aileron all have springs on the stick with zero being in there relaxed center positions while the throttle's zero is in the all the way down position.

Sometimes an ESC will go into program mode if you power up and the channel you're plugged into is not all the way down to idle. The other three channels (assuming you have an air transmitter) have a center postion for normal flight controls.
Edwin

Yes, this is true. The throttle must be "armed" before it will operate properly. Watch out for reverse operation on new installations. How do I know this? Five stiches on my right index finger says so.. [:@]

I always remove the prop when setting up a new electric plane. Otherwise I'm a nervous wreck. Way too many cuts on my hands from pre-electric days. In some ways electrics are more dangerous.

I do now, Villa.

CGr.