Crank the gen from the remote start switch and see if after 2 seconds the throttle opens wide open, if it does not open theres s good chance the governor throttle linkage has popped loose.
Find left side hole on top where spark plug is located.
In there is a throttle rod, gently see if you can lift it, if you can thats the problem. Just remove the top left row of screws and front and rear top screws and lift up the top cover, then snap the plastic holder back into the governor rod.
If this is not the problem check this thread where theres a guide with lots more info and flightsystems.com to help you good luck.
http://www.irv2.com/forums/f258/flig...ml#post4909229