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help me to solve engine problem

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lukaa

RC Newbie
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i bought new esc 120A and new motor 2845-5900kv surpass when i connect it to remote The engine spins freely, but when I hold the gear, it gets stuck at one point, starts vibrating, and loses power. what could be a problem
Screenshot_20260707-074841.webp
Screenshot_20260707-074941.webp
 
i bought new esc 120A and new motor 2845-5900kv surpass when i connect it to remote The engine spins freely, but when I hold the gear, it gets stuck at one point, starts vibrating, and loses power. what could be a problem View attachment 278303View attachment 278304

That's normal, it's called "cogging", and it is what happens if you overload a brushless motor. (sensored ones can keep pushing but you shouldn't overload those either)
 
Are you using the correct battery? Is it fully charged? Is your esc programed correctly?
Do you have the low voltage cutoff set for the battery you are using?
 

You should read this, then read it again! Theres a lot of useful info in this thread.

Welcome to RCTALK.COM!!! :cool::thumbs-up:😁

With the motor out of the car, does the car roll freely? No binding?

I am no expert but the 120a esc seems huge for a 2845 motor. There may be compatability issues.

What kind of rc are you installing all this into?

Is the motor the correct size for your RC?

Have you made any gearing or tire size changes to your RC or is it all stock?
 
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Low voltage cutoff is when your esc detects the minimum voltage of your battery. Looking at the picture of your battery i can not tell if its a 2s 3s or 4s. Usually esc's need to be programmed and calibrated. So if the esc is set for 3s and your running 2s battery it will think voltage is low. Did you follow the setup directions? Have you calibrated forward, neutral and reverse with your transmitter? Is your battery charged?
i dont know whats low voltage cutof I'm new in rc

View attachment 278308
 
Battery looks like 3s by the plug. 4 wires is what I see.
My 3s also have 4 wires.
There must be better markings on that battery.

Most certainly needs to be figured out before much else happens here.

I don't think a 5900kv motor will last long on 3s.
 
I think it's a 2S pack (7.4V on label).* Concur with suggestions above, I'm leaning towards the initial N/F/R ESC programming.

(edited to add) * D'Oh - it has all the voltages on the label?...
 
I'm sorry, but that ESC is the absolute worst thing I have ever used 🤢🤮.
Throw Away GIF by fwogs

There is no throttle calibration to be done on them. You just set your radio's throttle endpoints to 100% and the speed control looks for neutral point when you turn it on. It never worked right for me. Some people report they only work with certain radios. I should have tested it before mounting on my RC. Thankfully, seller refunded without any hassles. I wouldn't put it past the ESC as being the cause of your troubles.
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I got that one 👆👆by mistake. I thought I was getting one of the "blue 120A" ESCs that I have used many times before... the ones that have a setup button on the on/off switch (like shown below).
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1783466364439.webp

I got nothing to add. Sorry.
 
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