Hey,

I recently purchased a mamba max off ebay. I am now running it in my xxx bk2 with a 3300 matched pack.

Battery: 3300 matched
Motor: Mamba 7700 kv
Pinion: 21
Spur: 78
Motor Timing: Set Low

I basically have everything on the ESC set to factory default. While my motor does not get too hot, my esc gets hot enough so that I can only keep my hand on it for a few seconds before it gets uncomfortable.

Is the esc suppose to run this hot?

Shouldn't run that hot. The hot esc with a motor and batts that are not hot is the classic indication of being undergeared. Its a gearing issue, you need to go up a a few teeth on the pinion.

Get a temp gun and find out how hot the thing really is. I usually gear to 150F for the motor.

I might be wrong but this is how I see it.

Your ESC will get hot if your pinion is to big.
Your motor can get hot if your pinion is to big or to small.

If you put a smaller pinion on the load on the ESC goes down (less amps) ???

The sweet spot is when your ESC and motor are the same temperature ???

Quote from RC Monster -

"Although not always true, a rule of thumb is:
Hot motor, cool controller, cool batteries = undergeared
Cool motor, hot controller, hot batteries = overgeared
Warm motor, warm controller, warm batteries = happy components"


There are a few exceptions recognized, one being way overgeared where all 3 components run hot....

Thats a pretty good rule of thumb, but 21/78 in an off road car with a 7700Kv motor seems extremely high to me. I know my T4 has taller tires, and possibly a different transmission ratio, but when I tried a 7700Kv in it I had to use 12/87 to keep everything cool. It was still way too fast for an offroad track with that gearing. I do agree about getting a temp gun so you know exactly what temps youa re hitting. A few buddies and I always disagree how hot an ESC/motor feels before actually measuring it. But typically around 150F will burn my finger after a few seconds, higher than that and I can only touch it for one second or less.

Thanks for all your replies. I felt that I definitely over geared my motor. Simply because I dont have another pinion on me.
Ill order one soon enough. Thanks for your help!