Flipping tricopter

Hi-
Just finished a tricopter build using an HKPilot Mega Mini (I just wanted a cheap board I could put on a small, beater FPV platform, I know its no PixHawk, but it’s still running APM). Everything is wired correctly. I have double and triple checked. But for some reason, the copter flips to the right as soon as I throttle up. I don’t think it’s a problem with the board. Everything checks out in Planner when I hook it in. But as soon as the props start spinning, it just wants to roll to the right. Any suggestions on what may be going on here? This is my first tricopter build, so I’m a bit befuddled.
Thanks,
Eric

You might want to have a look at this thread regarding setting up a tricopter with an APM controller:

rcgroups.com/forums/showthread.php?t=1792924

Pay particular attention to the section titled, “Steps to reverse yaw direction in Mission Planner for the Tilt Servo” as that’s something that often surprises new APM tricopter users. You may have to reverse the servo channel on BOTH your RC Tx and the APM, or neither. Or some combo of the two.

Thanks. I don’t think that the yaw servo is the problem though. It seems like the front left motor is speeding up, causing it to roll right. Yaw servo seems to work fine. Unfortunately, I’m away from it for the night, so I can’t double check on the yaw in Planner. I’ll upload a video of what’s going on tomorrow if I can’t get things worked out. Appreciate the help in the meantime.