Hi, will I damage the ECU if I am running a HV setup?
Can't seem to find any threads on this.

ECU should be running a 9.9 Life Battery setup so I believe NO. check your manual for voltage requirements of ECU. My 170 and 140 both run Life 9.9 ECU batts.

Sorry if I wasn't clear with my question.
ECU I'll be using 3s LiFe. What I meant to say was I wanted to run 7.4v in my rx line for receiver and servos. Will the ECU be able to handle 7.4v from the throttle channel?

Recent versions of the Xicoy ECUs are rated for 4-10Volts on the 3 wire receiver input line. I can't confirm the current V10 ECU used with the 100G is the same, but it is likely.
I have at least one fellow jet flyer using a K170 and a HV receiver dual battery system (Lipo). I do not believe it is regulated at all. I'll check.

Barry should be able to confirm you are good with 7.4 from the receiver to the ECU.

Thanks for your reply Chris.
Do let me know when you have more information from your fellow flyer on the HV setup.