this has been driving me crazy for like two weeks now. one of my motors just randomly twitches or stutters, sometimes on the bench sometimes mid hover. it doesnt desync completely it just like.. hiccups. the other three are totally fine. ive already reseated all the signal wires and reflashed the ESC firmware. motor itself spins smooth by hand, no grinding or anything. i swapped the motor to a different ESC to see if the problem followed it and it did, so at this point i think the motor is actually bad?? but i dont see any obvious physical damage.

running AM32 on 40A individual ESCs if that matters. this started completely out of nowhere, never crashed this build, its been running perfect for months.

if the problem followed the motor to a different ESC then yeah it's almost certainly the motor. could be a partially broken winding or a loose magnet inside the bell ? you cant always feel that by spinning it by hand cause the resistance isnt obvious at low speed but under load or at certain RPMs it shows up. had a motor do almost the exact same thing to me, looked and felt fine, bench tested fine, but under any real load it would stutter. cracked it open and one of the stator windings had a hairline break. not repairable really.

before you bin the motor ? did you check the bullet connectors going to it? i had a similar stuttering issue last year and spent way too long blaming the motor itself. turns out one of the bullet connectors had a tiny bit of corrosion inside from flying near the coast and it was causing an intermittent connection. cleaning it out with some contact cleaner actually fixed it. probably not your issue since yours followed to a different ESC but figured id mention it cause its easy to miss and annoying when thats actually the cause.

if you already ruled that out then yeah just replace it, motors are cheap enough that its not worth the headache of debugging further.