been flying for about a year and a half now and ive gone through a few motors but honestly im still not totally sure when to replace vs when to just clean and keep going. like right now i have a motor on my 3inch that sounds a little rough, kind of gritty when you spin it. its not loud but you can feel and hear it isnt smooth. i took the top off and it doesnt look obviously dirty in there, the bearings dont feel super rough by hand but idk. the motor is maybe 8 months old, not sure how many actual hours on it.

do people regularly clean their motors or is that kind of pointless and you just run them till they die? ive seen people talk about flushing bearings with IPA or contact cleaner but ive also seen people say dont bother and just replace. curious what the actual experienced people here do for regular maintenance cause i feel like im either replacing too early or running them too long and i cant tell which

gritty feeling is usually the bearings starting to go. you can try flushing them with some isopropyl or electrical contact cleaner, spin the motor while you do it so it works through the bearing races, let it dry completely then add one tiny drop of thin oil like a sewing machine oil or even just wd40 specialist dry lube. sometimes this buys you another month or two sometimes the bearing is just worn and it makes no difference. for a 3inch cruiser motor thats not that expensive i honestly usually just swap it out rather than mess around, but for a bigger more expensive motor its worth trying to nurse it along first.

also worth checking the stator for any obvious heat discoloration ? if the copper windings look brown or darker than normal the motor has been running hot at some point and that can cause the varnish to break down and you get intermittent shorts. thats a replace for sure situation.

honestly i just run mine till they die lol. maybe thats bad practice but ive never had a motor just catastrophically fail mid flight, they always give you some warning like yours is doing now. the only time ive had a sudden failure was after a crash that i didnt inspect properly which is a whole other thing. if its just gritty i'd probably keep flying it for a bit and see if it gets worse, you'll know when its actually done