what is going on with my MMM V3?

hasnt been discussed by me.... and I am just going by HPI gearing charts. I havent run it on 6s yet obviously because it never started up :) I dont understand all of the nonsense with the flux and MMM, I dont hear issues with the E revo ERBE.

Anyway, I blipped the throttle with the motor out of the truck with the 25t pinion on to make sure all was good with my new batteries/connections etc, and then put it in the truck and then the weird thing happened. I tried it again and it happened again. It makes a glitching noise. I re armed both the esc and rx/tx countless times. And the fan responds to my throttle inputs LOL. I have had several castle products and this is my first issue. 15T pinion with a 44T spur seems way low if you ask me.