Hi, not entirely sure why it is not firing, not sure if it is a gearbox or motor issue. I have had the gearbox open a few times and everything is in order and it reassembled fine. I have just got a new battery in to day (7.4v 1300Mah LiPo) yet it is still not cycling and I am not entirely sure what the issue is. I made a quick video of me attempting to fire it in the hope it will help someone to help me, the sound you hear is the motor not the trigger I believe.