so ive been chasing this weird issue on my 5inch build for like two weeks now and its driving me insane. on startup maybe 3 out of 5 times one of my motors will twitch or stutter for half a second then just spins up normally like nothing happened. its always the same motor, back left. flew it a bunch and it seems totally fine in the air but im paranoid something is about to give out mid flight especially since im flying over my car.

ive reseated the motor connector, reflashed betaflight, checked the motor screws, even swapped props. didnt change anything. the motor itself is a 2306 2450kv, been on this frame for about 8 months. ESC is a 4in1 blheli32 setup. i dont think its a motor temp thing because it does it cold too. any ideas what this could even be

that twitching on the same motor every time is almost always a bad motor wire connection, like one of the three phase wires has an intermittent break in it, usually right where it enters the motor bell housing. ive seen this a dozen times. it looks fine externally but flex the wires a bit near the motor base while spinning it slowly by hand and youll probably feel or see it. if one phase drops out even momentarily the ESC gets confused and tries to re-sync which is exactly what that stutter looks like.

also worth checking if any of the tiny motor screws are slightly loose on the bottom of the motor itself, not just the mount screws. had one where the internal winding was just barely making contact because a screw backed out. either way id pull that motor and either resolder the wires or just swap it, 8 months of hard flying is enough to fatigue those wires especially if youve had any crashes.

could also just be the ESC desync thing with blheli32 on that particular motor, have you tried bumping up the motor timing a notch or enabling demag compensation if its not already on? i had something similar and messing with those settings in the blheli suite actually fixed it, though honestly i couldnt tell you exactly why it worked