I know what is going on with the 9400 rpm versus 10,500. If you make a rapid transistion from low throttle to high you will not get full rpm. How the device works is that it senses a change in throttle stick. When it senses a change it moves the servos to the new position then wait about 1/2 a second and starts synchronizing them. If the engines have not reached full RPM at the end of the 1/2 second it will pull the faster one back to match the slower one. There are a few solutions:

1. Move the stick slower
2. I have a custom chip that turns off synchronizing above 90% throttle (so you can get full power even if they are not in sync). I built this version for the Cessna 337.
3. I can increase the time after moving servos until it starts synchronizing for you.
4. move the stick back a little then go back to full throttle and it should go to max RPM.

As for the engine quitting I am not sure what could be causing this. Send me an email [email protected] with your phone number and I will call you to get into some more detailed questions to try to figure this out.