I have burned up two Heli-max AXE CPv3 E-boards (3 in 1 controller) and two tail motors have failed. I found an article on "Upgrading your Mini Electric Helicopter for protections for your motor electronics, main rotor drive gear and drive motors" at one of the RC forums (likely RCU) after posting separately here and talking with Heli-max technical support.

I have visually checked the wiring to the main motor and tested it to measure zero resistance with a digital multi-meter, as desired. As suggested in this article, I installed a 3 amp mini-fuse on the wiring to the tail motor, which I suspected to be the cause of the problem after replacing two of these tail motors. After test starting the AXE CPv3 both without and with the main motor connected, I shorted out this 3 amp mini-fuse and its replacement.

Should I next move up to a 5 amp mini-fuse?

I welcome all suggestions here.