I'm using Futaba T6EX with reciever connected correctly to Brain2. 40amp Hobbywing ESC. All controls work properly. The motor cuts off and on at high throttle. I tried different motors and Speed controllers. I purchaced a SCM, telemetry coupler hoping it would solve my problem, but I'm not sure how to connect it or if it will help.
To try to give you assistance, as we have written all over our site, we need some diagnostic files of your Flight Control Unit from which we can get various information.
Please read in the "Support" section the Sticky post "WHEN YOU ASK FOR SUPPORT" where you can find what we need, how to download it from the FCU and how to send it to us.
A 40A ESC is a very small size for modern engines and models, even for very small ones (you didn't tell us what is the model size you mounted it on). Are you sure it doesn't go into over current, over temperature and under voltage protection? Any beep from motor? Any blink sequence from the led of the ESC?
Have you reprogrammed the minimum and maximum throttle values? In the meantime, we suggest you reset the ESC to factory settings.