so this has been bugging me for like two weeks now and i cant figure it out. one of my rear motors on my 5inch freestyle build keeps stuttering, not every flight but maybe every third or fourth one. it doesnt do it on the bench when i spin them up in betaflight, only seems to happen when im actually flying and loading it up.

ive already reflow soldered the motor pads, swapped to a fresh prop on that arm, checked for any obvious shorts. ESCs are blheli32 running 32.8, motors are about 6 months old maybe 50 hours on them. not sure if its the motor itself starting to die or if its something with the ESC desync thing ive been reading about. any ideas before i just start throwing parts at it

desync was my first thought too but honestly after 50 hours on a freestyle motor it could just be bearings starting to go. the stutter under load but clean on the bench is kind of a classic sign of a motor thats on its way out. try swapping that motor to a different position and see if the problem moves with it, thats the quickest way to rule it out without buying anything.

also worth checking if your motor screws are all still tight, ive had one back out just enough to let the motor flex under hard throttle and it caused something similar.

had almost this exact thing happen on my build, turned out to be a cold solder joint on the ESC signal wire that only showed up under vibration. the bench test wont catch that because theres no airframe flex happening. i basically had to run my finger along every connection while the motors were spinning slowly and could feel a slight buzz on one that felt different. not super scientific but it worked lol