Hi
   I finally put together my tricopter using hk v2.1 quad board and i flashed it with XXcontrol_KR_TriCopter_v2_5.hex, The manual i followed is http://www.kkmulticopter.kr/index.html?modea=manual 

Everything works fine except i cant reverse the gyro. I set the roll pot to zero and connect the battery nothing happens.

After arming the board when tilt it to right the tail motor tilts to right. when i try to hover it the tri goes for spin 

need help.

Mate try lazyzero flash tool. You can directly reverse gyro from your pc so you can skip manual tx method.
You can read and write EEPROM value using lz tool.
www.lazyzero.de/en/modellbau/kkmulticopterflashtool

I had same problem ... my yaw was reverse and so tri was spining on its own axes when throttle up.

I simply used ch 5 which is already reversed.

try that.

Regards,
Atul

@Dharmik  thank you for you response, Am using diff avr programmer that i bought locally and lazyzero software does not detect it .

@atulrajguru9 Thanks alot using Motor 5 ch fixed it 

bottom line the XXcontrol_KR_TriCopter_v2_5.hex does not have gyro reversing.