Yup, it works.
It goes, it turns & it stops but, we have some issues.
1. The right motor does not seem as strong as the left motor.
Original theory: each motor should equally power each side.
On the first test runs, to successfully go straight, I needed to start off & constantly run the right motor & only kick in the left motor to increase speed or for steering correction.
When I tried (or Desteny, in the video) to take off from a stop using both controls (as it should be) the kart would keep pulling to the right.
2. I noticed, that when just pushing the kart by hand, it also pulls to the right.
For these initial tests, I used (3) 12v/12ah scooter batteries from (1) of the scooters to run both motors.
It seemed to last quite a while.
Desteny rode for ~15 minutes.
I went around front here a little while figuring out the controls then went around (4) city blocks (5) or (6) times.
Probably like 20 minutes so, over 1/2 hour of actual run time.
Toward the end, It wasn't quite as zippy but, it wasn't dead.
The batteries, wiring & controllers were all cool to the touch.
I charged but, didn't check the battery pack before our test runs.
After our test runs, I checked the battery pack, it tested @ 37.2v.
After ~(6) hours of charging they tested @ 42.8v.
3. Motor temp: the left motor was warm but, the right motor was noticeably warmer.
Causes could be;
1. Right motor is more warn.
2. Using right motor more during the test run to compensate for steering.
3. gear ratio issue.