Send MMM in for repair?

[Thirdgen89GTA]

I've got a car thats decided to start doing funky stuff.

Motor combo is a V3 MMM with a 1717. Power is supplied by a castle external bec, and its setup for 6S using twin 3S packs in series.

On an initial start if I give it fast throttle input the car will Jerk and then the ESC will reset as if it lost power. If the car is already rolling it doesn't do it.

Steps taken to diagnose:

• Tried batteries one at a time, both batteries do it.
• Tried the batteries + series connector with another ESC/Motor system from my 1/7th scale car.
• Checked the ESC battery connector for pitting or a bad solder joint.
• Looked for wiring breaks to the BEC.
• Lowered start power value in ESC to "Lowest".

Only things left to check are to try an external receiver pack to supply power, and install the other 1717 into the car.

I don't think its a motor issue, I'm thinking more on the ESC, or with the BEC.

Thoughts?