If the throttle is advanced and the engine does not rev-up, the voltage of the ignition battery could be too low or the pack could have a bad cell. That is what I found with my gasser.

The bottom line is that the ignition battery is as important as the glow plug for the glow engines. Always make sure it is in good shape and charged. Make a note on the number of flights you can have with a full charge and always charge the pack when that number is reached.

Measured the amps with 85% charged Turnigy pack. The draw is at 86A at full throttle.