That batt setup gives me nominal voltage between 3s and 4s Lipos, which should be great as far as power and reliability goes.
Are you questioning
MY solder joints?
I looked over them and they're all well soldered, no shorts. I used flux and made sure all the connections were not cold joints or partial joints while I was working on them. The wires on the battery and motor were not even as luke warm as the motor or battery.
It might have been voltage ripple with batteries that weren't not fully charged, so I'll try one step at a time after the battery charger gets here on thurday. I toned the punch down %30 so that might help a little.
Caps, different bullet connectors, lower gearing, fan, I should be able to find the problem somewhere. If none of those are the culprit my last guess would be the motor being 4-pole design where as a 2-pole might work better. But there is no way I'm changing my motor.