Poorly tinned wires
 

Could poorly tinned wires cause the car to cog?

Thanks!

Cogging is usually caused by bad sensor wire or the sensor itself. Swap out the wire first. (easy part).

Poorly tinned wires
 

The motor sensor?

Could be you have none.....

A sensorless system has only 3 thick motor wires, a sensored system has as extra a small 6 wire cable connected between motor and ESC.

If you do not have a sensor cable then cogging is quite normal, the motor needs to get some revs before the ESC will detect the rotor position. The motor coils are also the sensors for the ESC but it will not give any signal when the rotor is standing still. Without the position detection at no and very low rpm the ESC is having a somekind own live until the rotation speed is high enough to buld a feedback signal.

With a sensored system there are electronic magnetic sensors which will see the position of the rotor at any time so from zerro RPM the ESC knows how to control the motor.

Yes. Like Roelof stated...Your motor may not have one if it's a sensorless system. You'll either see a 6 wire lead from motor to ESC or you won't. This is in addition to the main 3 wires from motor to ESC.

New motor installed? Try recalibrating the ESC, if still cogs Try smaller pinion. Make sure you set your Voltage cutoff correctly.

Poorly tinned wires
 

Not a new motor. Just put new wires in. Changed the sensor wire & the cogging stopped on load but happens sometimes after landing a jump.