Vic
Hi
How are you?
I am pretty new to this as well, i have not even manage to fly this machine
Still getting alot of help from Good Brothers from the thread
I had the same problem like yours, tail spinning, it was the belt issue
The adjustment is made by moving the tail boom. If you were to look at the Portion where the frame connects to the tail boom where u can actually see the Belt, there is 4 screws securing the position of the tail boom. u have to unscrew, pull the tail boom back and tighten.
But my problem was a lil bit on the severe stage, where the belt got off the aligned position and brushed against the guide screws.
I only truly solved the problem after changing the belt- just tight it enough to hold the Teeth in position, too tight or too loose is bad.
logically i believe if it spins and you cannot counter the spin by using controls, then there is definitely lost of power on the tail - i hope i am right

i am a newbie as well, shouldn't be giving professional advice.. haha
Good luck flying bro
Cheers