3s motor lost all it's torque

[The Bean]

My 3s VXL motor (Slash 4x4) lost so much torque, that it can't accelerate on grass, on 2s and 3s.
Should I upgrade to a 2400kv?
Could it be because it became so hot that it boiled water a couple of months ago? (>100°C, 212°F)

 

[SrC]

Overheating the motor's magnets will absolutely decrease a motors torque no doubt. Repeated overheating accelerates the effect. Becomes an accumulative degradation over time. Some motors worse than others.
The magnetism gets very weak with extreme high temps. One sure sign is that braking also becomes much weaker.
Some motors have better magnets than others. And Magnet quality matters. Why better motors cost more.
Over time some motors just get weaker because of this. Quality of the Rare Earth magnets in BLX motors vary. You pay more for them in quality brands.


Edited.

 

[pug]

Definitely weakened the magnets with that temperature. If you upgrade to 2400kv, you will lose a good amount of speed, but you shouldn't have temperature issues.

 

[SrC]

+1
The higher the kv, generally the higher the RPMs, but you get way less torque. An inverse relationship with Torque and Speed (RPM's).
Over gearing a high Kv motor will overheat it. Watch your gearing and temps, with temp gun in hand.
I like to gear my motors where external motor temps don't exceed 150-160F. This is subjective to the weather. Winter versus Summer running.
With better Fans picking up the slack as needed.

 

[Senton_Prime]

Sounds like motor bearings are shot!!

 

[SrC]

Could be
Will never know if you don't open up your motor and have a close look.

 

[Jerry-rigged]

I agree, sounds like you cooked it. And the 2400 may not be an upgrade if you can't throw a big enough pinion in there. (IDK the Slash's gearing range)

 

[The Bean]

Right now I have the smallest pinion I could fit, and the 2400kvs have the same diameter as my current motor (36XX can).

Should I get a MAXX motor and swap connectors, or get something with good reviews off of E-Bay?

 

[Jerry-rigged]

GoolRC motors are pretty decent, and really cheap. Here is a 3670 2850kv for under $30 -
https://www.amazon.com/GoolRC-Origi...or&qid=1644959615&sprefix=3670,aps,277&sr=8-1
I have a GoolRC 3660 3800kv that I ran in my granite for about two years, now it is pushing my Tekno SCT410. Strong motor, long lasting, runs fast.

If you have burned up a 3660, then you will probably want the longer can 3670. That 2850 is pretty close to your existing motor, add a few teeth and you should be at similar speeds. You may even consider going for a 2000kv on 4s - that will also help keep temps down.

 

[The Bean]

GoolRC motors are pretty decent, and really cheap. Here is a 3670 2850kv for under $30 -
https://www.amazon.com/GoolRC-Original-2850KV-Brushless-Sensorless/dp/B07Q9Q9XCG/ref=sr_1_1?keywords=3670+brushless+motor&qid=1644959615&sprefix=3670,aps,277&sr=8-1
I have a GoolRC 3660 3800kv that I ran in my granite for about two years, now it is pushing my Tekno SCT410. Strong motor, long lasting, runs fast.

If you have burned up a 3660, then you will probably want the longer can 3670. That 2850 is pretty close to your existing motor, add a few teeth and you should be at similar speeds. You may even consider going for a 2000kv on 4s - that will also help keep temps down.

It's actually a 3656, so the new motor would be 14mm longer.
That motor you linked seems quite good, I'll look into that