Something up with Mamba Max?

[Arct1k]

Gearing for mid/high 30's with that setup should be ok - what are your motor temps?

Check for any binding etc on the drive chain - If you have not added an additional capacitor to the esc I would STRONGLY recommend this. I've had 2 MM blow up in this configuration 4s/mm 9xl prior to putting caps on. Since adding an extra 2700uf caps I've had no issues.

If it help or convinces you Mike does exactly the same thing - It is a $5 fix that lowers temps a fair bit.